Problem:
Score : 200 points

Problem Statement

Given are two strings S and T.

Let us change some of the characters in S so that T will be a substring of S.

At least how many characters do we need to change?

Here, a substring is a consecutive subsequence. For example, xxx is a substring of yxxxy, but not a substring of xxyxx.

Constraints

The lengths of S and T are each at least 1 and at most 1000.

The length of T is at most that of S.

S and T consist of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S
T

Output

Print the minimum number of characters in S that need to be changed.

Sample Input 1

cabacc
abc

Sample Output 1

1

For example, changing the fourth character a in S to c will match the second through fourth characters in S to T.

Since S itself does not have T as its substring, this number of changes - one - is the minimum needed.

Sample Input 2

codeforces
atcoder

Sample Output 2

6

Solution in Rust (1.42.0) (judge verdict: Accepted)

#![allow(unused_imports)]

// language: Rust(1.42.0)
// check available crates on AtCoder at "https://atcoder.jp/contests/language-test-202001"
// My Library Repositry is at "https://github.com/Loptall/sfcpl"

/*
    水コーダーになれてうれしいです
*/

// from std...
use std::cmp::{
    max, min, Ordering,
    Ordering::{Equal, Greater, Less},
    Reverse,
};
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
use std::convert::TryInto;
use std::fmt;
use std::mem::swap;
use std::num::{NonZeroU32, ParseIntError};
use std::ops::{
    Add, AddAssign, BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Div, DivAssign,
    Index, IndexMut, Mul, MulAssign, Neg, Rem, RemAssign, Shl, ShlAssign, Shr, ShrAssign, Sub,
    SubAssign,
};
use std::process::exit;
use std::{f32, f64, i128, i16, i32, i64, i8, isize, u128, u16, u32, u64, u8, usize};

// Dep' crates are...
use itertools::*;
use itertools_num::*;
use lazy_static::lazy_static;
use maplit::{btreemap, btreeset, hashmap, hashset};
use num_bigint::{BigInt, BigUint};
use num_complex::Complex;
use num_integer::{binomial, gcd, lcm, multinomial, Integer};
use num_rational::Rational;
use num_traits::{
    clamp, one, pow, zero, Num, NumAssignOps, NumOps, One, Pow, Signed, Unsigned, Zero,
};
use permutohedron::Heap;
use proconio::{
    derive_readable, fastout, input, is_stdin_empty,
    marker::{Bytes, Chars, Isize1, Usize1},
};
use rand::random;

pub use visualize::*;
pub mod visualize {
    use itertools::*;
    pub trait Visualize {
        fn visualize(&self, split: &str);
        fn continuous(&self) {
            self.visualize("");
        }
        fn spaces(&self) {
            self.visualize(" ");
        }
        fn lines(&self) {
            self.visualize("\n");
        }
    }
    macro_rules ! impl_vis_for_sized {($ ($ t : ty ) ,+ ) => {$ (impl Visualize for $ t {fn visualize (& self , _split : & str ) {print ! ("{}" , self ) ; } } ) + } ; }
    impl_vis_for_sized! {usize , u8 , u16 , u32 , u64 , u128 , isize , i8 , i16 , i32 , i64 , i128 , String , & str , char }
    impl<T: std::fmt::Display> Visualize for [T] {
        fn visualize(&self, split: &str) {
            print!("{}", self.iter().join(split));
        }
    }
    #[test]
    fn fmt() {
        let a = 2;
        a.visualize("");
        let b = "str";
        b.visualize("");
        let c = vec![1, 2, 3];
        c.visualize(" ");
        c.visualize("\n");
    }
    /// macro to output answer improved to println
    /// this macro will print '\n' at the last.
    /// # Patterns
    /// `,`, it means one space, it formats the elements, which is before, space-split.
    /// And insert a space after the prefix, unless it is at last.
    /// `=>`, it means empty string, it formats the element, witch is before, without any split.
    /// And insert nothing between two element.
    /// `;`, it means newline(\n), it formats the element, witch is before, newline-split.
    /// And insert a newline after the prefix, unless it is at last.
    /// # Eample
    /// ```
    /// #[test]
    /// fn vis_test() {
    ///     let a = 1;
    ///     let b = 2;
    ///     let c = 3;
    ///     let v = vec!['a', 'b', 'c'];
    ///     // single element test ...
    ///     vis!(a); // 1\n
    ///     vis!(a,); // 1\n
    ///     vis!(a =>); // 1\n
    ///     vis!(a;); // 1\n
    ///     println!();
    ///     vis!(a + b); // 3\n
    ///     println!();
    ///     vis!(v); // a b c\n
    ///     vis!(v,); // a b c\n
    ///     vis!(v =>); // abc\n
    ///     vis!(v;); // a\nb\nc\n
    ///     println!();
    ///     // multi elements connected by common operater test ...
    ///     println!();
    ///     vis!(a, b); // 1 2\n
    ///     vis!(a, b, c); // 1 2 3\n
    ///     vis!(a, b, c;); // 1 2 3\n
    ///     println!();
    ///     vis!(a => b); // 12\n
    ///     vis!(a => b => c); // 123\n
    ///     vis!(a => b => c ,); // 123\n
    ///     println!();
    ///     vis!(a; b); // 1\n2\n
    ///     vis!(a; b; c); // 1\n2\n3\n
    ///     vis!(a; b; c =>); // 1\n2\n3\n
    ///     println!();
    ///     // multi elements connected by different operater test ...
    ///     vis!(a, b; c); // 1 2\n3\n
    ///     vis!(a; b, c); // 1\n2 3\n
    ///     vis!(a => b, c); // 12 3\n
    ///     vis!(a; b => c); // 1\n23\n
    ///     println!();
    ///     vis!(a, v); // 1 a b c\n;
    ///     vis!(a, v;); // 1 a\nb\nc\n;
    ///     vis!(a => v =>); // 1abc\n;
    ///     println!("\d");
    ///     // panic!()
    /// }
    /// ```
    #[macro_export]
    macro_rules ! vis {() => {println ! () ; } ; ($ last : expr ; ) => {$ last . lines () ; vis ! () } ; ($ last : expr => ) => {$ last . continuous () ; vis ! () ; } ; ($ last : expr $ (, ) ? ) => {$ last . spaces () ; vis ! () ; } ; ($ first : expr ; $ ($ rest : tt ) * ) => {$ first . lines () ; println ! () ; vis ! ($ ($ rest ) * ) ; } ; ($ first : expr => $ ($ rest : tt ) * ) => {$ first . continuous () ; vis ! ($ ($ rest ) * ) ; } ; ($ first : expr , $ ($ rest : tt ) * ) => {$ first . spaces () ; print ! (" " ) ; vis ! ($ ($ rest ) * ) ; } ; }
    #[test]
    fn vis_test() {
        let a = 1;
        let b = 2;
        let c = 3;
        let v = vec!['a', 'b', 'c'];
        vis!();
        vis!(a);
        vis!(a,);
        vis ! (a => );
        vis ! (a ; );
        println!();
        vis!(a + b);
        println!();
        vis!(v);
        vis!(v,);
        vis ! (v => );
        vis ! (v ; );
        println!();
        println!();
        vis!(a, b);
        vis!(a, b, c);
        vis ! (a , b , c ; );
        println!();
        vis ! (a => b );
        vis ! (a => b => c );
        vis ! (a => b => c , );
        println!();
        vis ! (a ; b );
        vis ! (a ; b ; c );
        vis ! (a ; b ; c => );
        println!();
        vis ! (a , b ; c );
        vis ! (a ; b , c );
        vis ! (a => b , c );
        vis ! (a ; b => c );
        println!();
        vis!(a, v);
        vis ! (a , v ; );
        vis ! (a => v => );
    }
}

pub use consts::*;
pub mod consts {
    pub const MOD10E9_7: usize = 1000000007; // 10 ^ 9 + 7
    pub const MOD99_: usize = 998244353;
    pub const MAX: usize = std::usize::MAX; // = 2 ^ 64 - 1 = 18446744073709551615 ≈ 1.8 * 10 ^ 19
    pub const INF: usize = 2000000000000000000; // MAX / 9 < 2 * 10e18 < MAX / 10
    pub const FNI: i64 = -2000000000000000000; // == -(INF as i64)
    pub const PI: f64 = std::f64::consts::PI; // 3.141592653589793 -- 10 ^ -15
    pub const ASCII_A_LARGE: u8 = 65;
    pub const ASCII_A_SMALL: u8 = 97;
    pub const ASCII_0: u8 = 48;
    pub const ADJ4: &[(isize, isize); 4] = &[(1, 0), (0, 1), (-1, 0), (0, -1)];
    pub const ADJ8: &[(isize, isize); 8] = &[
        (1, 0),
        (1, 1),
        (0, 1),
        (-1, 1),
        (-1, 0),
        (-1, -1),
        (0, -1),
        (1, -1),
    ];
}
// code...
// #[fastout]
fn main() {
    input! {
        s: Chars,
        t: Chars
    }

    let mut ans = INF;
    for start in 0..=s.len() - t.len() {
        let ss = &s[start..start + t.len()];
        let c = (0..t.len()).filter(|&x| ss[x] != t[x]).count();
        ans = min(ans, c);
    }

    vis!(ans);
}