#include<bits/stdc++.h>
using namespace std;
const int N=2005;
int f[N][N];
int main () 
{
	string word1,word2;
	cin>>word1>>word2;
	for(int i=1;i<=word1.size();i++) f[i][0]=i;
	for(int j=1;j<=word2.size();j++) f[0][j]=j;
	for(int i=1;i<=word1.size();i++)
	{
		for(int j=1;j<=word2.size();j++)
		{
			if(word1[i]==word2[j]) f[i][j]=f[i-1][j-1];
			else f[i][j]=min(f[i-1][j],f[i][j-1])+1;
		}
	}
	cout<<f[word1.size()][word2.size()];
	return 0;
}