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)

#[allow(unused_imports)]
use std::cmp::*;
#[allow(unused_imports)]
use std::collections::*;
#[allow(unused_imports)]
use std::iter::*;
#[allow(unused_imports)]
use std::*;

macro_rules! test {
    ($($input:expr => $output:expr),* $(,)*) => {
#[test]
        fn solve_test() {
            $(
                {
                    let mut out = Vec::<u8>::new();
                    solve($input,&mut out);
                    let out_str =str::from_utf8(&out).unwrap();
                    assert_eq!(&out_str, &$output);
                }
            )*
        }
    };
}
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
#[allow(unused_mut)]
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let mut s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};

    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };

    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };

    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };

    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, isize1) => {
        read_value!($iter, isize) - 1
    };
    ($iter:expr,str) => {
        $iter.next().unwrap()
    };

    ($iter:expr, $t:tt) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

macro_rules! stdin {
    () => {{
        use std::io::Read;
        let mut s = String::new();
        std::io::stdin().read_to_string(&mut s).unwrap();
        s
    }};
}

#[allow(dead_code)]
fn to_yesno(yesno: bool) -> &'static str {
    if yesno {
        "Yes"
    } else {
        "No"
    }
}

fn main() {
    let mut out = std::io::stdout();

    solve(&stdin!(), &mut out);
}

#[allow(unused_mut)]
fn solve<W: std::io::Write>(src: &str, out: &mut W) {
    #[allow(unused_macros)]
    macro_rules! out {
        ($arg:expr) => {{
            let _ = out.write_fmt(format_args!("{}",$arg));
        }};
        ($fmt:expr, $($args:tt)*) => {{
            let _ = out.write_fmt(format_args!($fmt, $($args)*));
        }};
    }
    #[allow(unused_macros)]
    macro_rules! outln {
        ($arg:expr) => {{
            out!("{}\n",$arg);
        }};
        ($fmt:expr, $($args:tt)*) => {{
            out!(concat!($fmt, "\n"), $($args)*);
        }};
    }

    input! {
        source = src,
        s:chars,
        t:chars,
    }
    let mut ans = vec![None; s.len()];
    for (i, ti) in t.iter().enumerate() {
        for (j, si) in s.iter().enumerate() {
            if ti == si {
                ans[j] = Some(i);
            }
        }
    }
    let mut max_c = 0;
    let mut i: isize = -1;
    let mut c = 0;
    for (vi, &v) in ans.iter().enumerate() {
        if let Some(v) = v {
            if vi >= v && ans.len() as isize - vi as isize >= t.len() as isize - v as isize {
                let v = v as isize;
                if i == -1 {
                    i = v;
                }
                if v == i {
                    i += 1;
                    c += 1;
                    max_c = max(max_c, c);
                } else {
                    c = 1;
                    i = v + 1;
                }
                continue;
            }
        }
        c = 0;
        i = -1;
    }
    out!(t.len() - (max_c));
}

test! {}