H

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <string>
#include <map>
#include <cmath>
#include <vector>

#define Faster ios::sync_with_stdio(false),cin.tie(0)
#define Read freopen("in.txt","r",stdin),freopen("out.txt","w",stdout)
#define Close fclose(stdin),fclose(stdout)
const int maxn = 105;
using namespace std;
const int MOD = 1e9+7;
typedef long long ll;

char s1[maxn];
char s2[maxn];
int dp[maxn][maxn];
int len;
int ans[maxn];

int main(){
    Faster;
    while(~scanf("%s%s", s1, s2)){
        len = strlen(s1);
        memset(dp, 0, sizeof(dp));
        for(int j = 0;j < len; j++){    //j为尾
            for(int i = j;i >= 0;i--){        //i为头
                dp[i][j] = dp[i+1][j] + 1;    //每个都单独刷一次
                for(int k = i+1;k <= j;k++){
                    if(s2[i] == s2[k]){
                        dp[i][j] = min(dp[i][j], (dp[i+1][k]+dp[k+1][j]));
                    }
                }
            }
        }
        for(int i = 0;i < len;i++){
            ans[i] = dp[0][i];
        }
        for(int i = 0;i < len;i++){
            if(s1[i] == s2[i]){
                ans[i] = ans[i-1];    //对应位置相等的话，就不用刷新
            }
            else{
                for(int j = 0;j < i;j++){
                    ans[i] = min(ans[i], ans[j] + dp[j+1][i]);    //寻找j来分割区间的最优解
                }
            }
        }
        printf("%d
", ans[len-1]);
    }
    return 0;
}