luoguP2758

#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
const int N=30+5,INF=0x3f3f3f3f,MOD=1e9+7;
const int dx[]={1,-1,0,0},dy[]={0,0,1,-1};
typedef long long LL;
string a,b;
int lena,lenb,k;
int main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);cout.tie(nullptr);
	cin>>a>>b;
	lena = a.size(),lenb = b.size();
	a = " "+a,b = " "+b;
	vector<vector<int>>dp(lena+1,vector<int>(lenb+1));
	for(int i=0;i<=lena;i++)dp[i][0] = i;
	for(int i=0;i<=lenb;i++)dp[0][i] = i;
	for(int i=1;i<=lena;i++){
		for(int j=1;j<=lenb;j++){
			k = 1;
			if(a[i]==b[j])k = 0;
			dp[i][j] = min({dp[i-1][j]+1,dp[i][j-1]+1,dp[i-1][j-1]+k});
		}
	}
	cout<<dp[lena][lenb];
	return 0;
}