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 C# (.NET Core 3.1.201) (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            string t = Console.ReadLine();

            IEnumerable<string> sList = new string[] { s };
            IEnumerable<string> tList = new string[] { t };

            for (var i = 0; i < t.Length; i++)
            {
                foreach (var tt in tList)
                {
                    foreach (var ss in sList)
                    {
                        if (ss.Contains(tt))
                        {
                            Console.WriteLine(i);
                            return;
                        }
                    }
                }
                sList = ForMatch(sList, t.Length);
                tList = ForMatch(tList, t.Length);
            }
            Console.WriteLine(t.Length);
        }

        static IEnumerable<string> ForMatch(IEnumerable<string> strs, int max)
        {
            foreach (string str in strs)
            {
                int? first = null;
                for (int i = 0; i < str.Length; i++)
                {
                    bool isZero = str.Substring(i, 1) == "0";
                    if (!first.HasValue && isZero) first = i;
                    if (isZero && (!first.HasValue || i - first < max))
                    {
                        var list = str.Select(n => n.ToString()).ToList();
                        list[i] = "0";
                        yield return string.Join(string.Empty, list);
                    }
                }
            }
        }
    }
}