diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9658366..9cf89aa 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -129,3 +129,47 @@ jobs:
 
       - name: expand.py tests
         run: bash ./.github/workflows/test-expand.sh
+
+  verify:
+    name: Verify
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Setup `1.47.0-x86_64-unknown-linux-gnu`
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.47.0-x86_64-unknown-linux-gnu
+          override: true
+          profile: minimal
+
+      - name: Setup Python 3.9
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.9'
+
+      - name: Install `oj`
+        run: pip install online-judge-tools
+
+      - name: cargo-build
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: --release --examples
+
+      - name: Verify
+        run: |
+          NAMES=(
+            convolution_mod
+            static_range_sum
+            sum_of_floor_of_linear
+            unionfind
+          )
+          for name in "${NAMES[@]}"; do
+            oj d "https://judge.yosupo.jp/problem/$name" -ad "/tmp/$name"
+          done
+          for name in "${NAMES[@]}"; do
+            oj t -d "/tmp/$name" -t 10 -c "./target/release/examples/library-checker-${name//_/-}" --judge-command ~/.cache/online-judge-tools/library-checker-problems/*/"$name"/checker
+          done
diff --git a/Cargo.toml b/Cargo.toml
index 5348943..463b124 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,5 +15,7 @@ publish = false
 [dependencies]
 
 [dev-dependencies]
+input = { path = "./crates/input" }
 proconio = "=0.3.6"
+proconio-derive = "0.2.1"
 rand = "0.7.3"
diff --git a/crates/input/Cargo.toml b/crates/input/Cargo.toml
new file mode 100644
index 0000000..feab978
--- /dev/null
+++ b/crates/input/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "input"
+version = "0.1.0"
+authors = ["rust-lang-ja Developers"]
+edition = "2018"
+description = "Provides an `input!` macro for the `examples`."
+license = "CC0-1.0"
+publish = false
+
+[dependencies]
diff --git a/crates/input/src/lib.rs b/crates/input/src/lib.rs
new file mode 100644
index 0000000..ea7cd6a
--- /dev/null
+++ b/crates/input/src/lib.rs
@@ -0,0 +1,96 @@
+//! A simple `input!` macro with minimal functionality.
+//!
+//! ```no_run
+//! #[macro_use]
+//! extern crate input as _;
+//!
+//! fn main() {
+//!     input! {
+//!         a: [u64],
+//!     }
+//! }
+//! ```
+
+use std::{
+    fmt,
+    io::{self, Read},
+    str::{FromStr, SplitAsciiWhitespace},
+};
+
+#[macro_export]
+macro_rules! input {
+    ($($tt:tt)*) => {
+        let mut __scanner = $crate::Scanner::new().unwrap();
+        $crate::input_inner!(@scanner(__scanner), @tts($($tt)*));
+        ::std::mem::drop(__scanner);
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! input_inner {
+    (@scanner($scanner:ident), @tts()) => {};
+    (@scanner($scanner:ident), @tts(mut $single_tt_pat:tt : $readable:tt)) => {
+        let mut $single_tt_pat = $crate::read!(from $scanner { $readable });
+    };
+    (@scanner($scanner:ident), @tts($single_tt_pat:tt : $readable:tt)) => {
+        let $single_tt_pat = $crate::read!(from $scanner { $readable });
+    };
+    (@scanner($scanner:ident), @tts(mut $single_tt_pat:tt : $readable:tt, $($rest:tt)*)) => {
+        $crate::input_inner!(@scanner($scanner), @tts(mut $single_tt_pat: $readable));
+        $crate::input_inner!(@scanner($scanner), @tts($($rest)*));
+    };
+    (@scanner($scanner:ident), @tts($single_tt_pat:tt : $readable:tt, $($rest:tt)*)) => {
+        $crate::input_inner!(@scanner($scanner), @tts($single_tt_pat: $readable));
+        $crate::input_inner!(@scanner($scanner), @tts($($rest)*));
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! read {
+    (from $scanner:ident { [$tt:tt] }) => {
+        $crate::read!(from $scanner { [$tt; $crate::read!(from $scanner { usize })] })
+    };
+    (from $scanner:ident  { [$tt:tt; $n:expr] }) => {
+        (0..$n).map(|_| $crate::read!(from $scanner { $tt })).collect::<Vec<_>>()
+    };
+    (from $scanner:ident { ($($tt:tt),+) }) => {
+        ($($crate::read!(from $scanner { $tt })),*)
+    };
+    (from $scanner:ident { $ty:ty }) => {
+        $scanner.parse::<$ty>()
+    };
+}
+
+#[doc(hidden)]
+pub struct Scanner {
+    words: SplitAsciiWhitespace<'static>,
+}
+
+impl Scanner {
+    pub fn new() -> io::Result<Self> {
+        let mut buf = String::with_capacity(1024);
+        io::stdin().read_to_string(&mut buf)?;
+        let words = Box::leak(buf.into_boxed_str()).split_ascii_whitespace();
+        Ok(Self { words })
+    }
+
+    /// Parses the next word.
+    ///
+    /// # Panics
+    ///
+    /// Panics if:
+    ///
+    /// - reached the end of input.
+    /// - the word is not successfully parsed.
+    pub fn parse<T>(&mut self) -> T
+    where
+        T: FromStr,
+        T::Err: fmt::Display,
+    {
+        let word = self.words.next().expect("reached the end of input");
+        word.parse()
+            .unwrap_or_else(|e| panic!("could not parse {:?}: {}", word, e))
+    }
+}
diff --git a/examples/library-checker-convolution-mod.rs b/examples/library-checker-convolution-mod.rs
new file mode 100644
index 0000000..9e179b0
--- /dev/null
+++ b/examples/library-checker-convolution-mod.rs
@@ -0,0 +1,27 @@
+#[macro_use]
+extern crate input as _;
+
+use ac_library_rs::{convolution, modint::ModInt998244353 as Mint};
+use std::fmt;
+
+fn main() {
+    input! {
+        n: usize,
+        m: usize,
+        a: [Mint; n],
+        b: [Mint; m],
+    }
+
+    print_oneline(convolution::convolution(&a, &b));
+}
+
+fn print_oneline<I: IntoIterator<Item = T>, T: fmt::Display>(values: I) {
+    println!(
+        "{}",
+        values
+            .into_iter()
+            .map(|v| v.to_string())
+            .collect::<Vec<_>>()
+            .join(" "),
+    )
+}
diff --git a/examples/library-checker-static-range-sum.rs b/examples/library-checker-static-range-sum.rs
new file mode 100644
index 0000000..a4a5d8b
--- /dev/null
+++ b/examples/library-checker-static-range-sum.rs
@@ -0,0 +1,25 @@
+#[macro_use]
+extern crate input as _;
+#[macro_use]
+extern crate proconio_derive as _;
+
+use ac_library_rs::fenwicktree::FenwickTree;
+
+#[allow(clippy::needless_collect)]
+#[fastout]
+fn main() {
+    input! {
+        n: usize,
+        q: usize,
+        r#as: [u64; n],
+        lrs: [(usize, usize); q],
+    }
+
+    let mut fenwick = FenwickTree::new(n, 0);
+    for (i, a) in r#as.into_iter().enumerate() {
+        fenwick.add(i, a);
+    }
+    for (l, r) in lrs {
+        println!("{}", fenwick.sum(l, r));
+    }
+}
diff --git a/examples/library-checker-sum-of-floor-of-linear.rs b/examples/library-checker-sum-of-floor-of-linear.rs
new file mode 100644
index 0000000..78c3ca6
--- /dev/null
+++ b/examples/library-checker-sum-of-floor-of-linear.rs
@@ -0,0 +1,17 @@
+#[macro_use]
+extern crate input as _;
+#[macro_use]
+extern crate proconio_derive as _;
+
+use ac_library_rs::math;
+
+#[fastout]
+fn main() {
+    input! {
+        nmabs: [(i64, i64, i64, i64)],
+    }
+
+    for (n, m, a, b) in nmabs {
+        println!("{}", math::floor_sum(n, m, a, b));
+    }
+}
diff --git a/examples/library-checker-unionfind.rs b/examples/library-checker-unionfind.rs
new file mode 100644
index 0000000..b6e1081
--- /dev/null
+++ b/examples/library-checker-unionfind.rs
@@ -0,0 +1,22 @@
+#[macro_use]
+extern crate input as _;
+
+use ac_library_rs::dsu::Dsu;
+
+fn main() {
+    input! {
+        n: usize,
+        queries: [(u8, usize, usize)],
+    }
+
+    let mut dsu = Dsu::new(n);
+    for (kind, u, v) in queries {
+        match kind {
+            0 => {
+                dsu.merge(u, v);
+            }
+            1 => println!("{}", u8::from(dsu.same(u, v))),
+            _ => unreachable!(),
+        }
+    }
+}