#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<cmath>
#include<list>
#include<vector>
#include<queue>
#include<ctime>
#include<cstdlib>
#define maxn 2010
using namespace std;
typedef long long ll;
typedef unsigned long wf;
typedef unsigned int u32;
typedef unsigned long long u64;
int n,f[maxn][maxn];
string a,b;
int main(){
    cin>>a>>b;
    int n=a.length(),m=b.length();  
    for(int i=1;i<=n;i++) f[i][0]=i;
    for(int i=1;i<=m;i++) f[0][i]=i;
    for(int i=1;i<=n;i++) 
    	for(int j=1;j<=m;i++) 
			f[i][j]=min(min(f[i-1][j]+1,f[i][j-1]+1),f[i-1][j-1]+(a[i-1]!=b[j-1]));
	cout<<f[n][m];
	return 0;
}