#include <bits/stdc++.h>
using namespace std;
string s1,s2;
int f[2005][2005];
int main(){
	cin>>s1>>s2;
	int len1=s1.size();
	int len2=s2.size();
	for(int i=0;i<len1;i++){
		for(int j=0;j<len2;j++){
			if(s1[i]==s2[j]){
				f[i][j]=f[i-1][j-1];
			}else{
				f[i][j]=min(f[i-1][j],min(f[i][j-1],f[i-1][j-1]))+1;
			}
		}
	} 
	printf("%d",f[len1-1][len2-1]);
	return 0;
}