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: Wrong Answer)

use std::cmp::min;
fn main() {
    let mut reader = TokenReader::new();
    let s: Vec<char> = reader.next::<String>().chars().collect();
    let t: Vec<char> = reader.next::<String>().chars().collect();

    let mut ans = t.len();

    for start in 0..(s.len() - t.len()) {
        let mut diff = 0;
        for i in 0..t.len() {
            if &t[i] != &s[start + i] {
                diff += 1;
            }
        }
        ans = min(ans, diff);
    }
    println!("{}", ans);
}

// ---------- Begin Scanner ----------
#[allow(dead_code)]

use std::fmt::Debug;
use std::str::FromStr;

pub struct TokenReader {
    reader: std::io::Stdin,
    tokens: Vec<String>,
    index: usize,
}

impl TokenReader {
    pub fn new() -> Self {
        Self {
            reader: std::io::stdin(),
            tokens: Vec::new(),
            index: 0,
        }
    }

    pub fn next<T>(&mut self) -> T
    where
        T: FromStr,
        T::Err: Debug,
    {
        if self.index >= self.tokens.len() {
            self.load_next_line();
        }
        self.index += 1;
        self.tokens[self.index - 1].parse().unwrap()
    }

    pub fn vector<T>(&mut self) -> Vec<T>
    where
        T: FromStr,
        T::Err: Debug,
    {
        if self.index >= self.tokens.len() {
            self.load_next_line();
        }
        self.index = self.tokens.len();
        self.tokens.iter().map(|tok| tok.parse().unwrap()).collect()
    }

    fn load_next_line(&mut self) {
        let mut line = String::new();
        self.reader.read_line(&mut line).unwrap();

        self.tokens = line.split_whitespace().map(String::from).collect();
        self.index = 0;
    }
}

// ---------- End Scanner ----------