#include<iostream>
#include<string>
using namespace std;
string a,b;
int la,lb;
int f[2010][2010];
int min(int a,int b,int c){
   if(a<b&&a<c)return a;
   if(b<a&&b<c)return b;
   if(c<a&&c<b)return c;
}
int main(){
   cin>>a>>b;
   la=a.size();
   lb=b.size();
   a=" "+a;
   b=" "+b;
   for(int i=0;i<=la;i++)f[i][0]=i;
   for(int i=0;i<=lb;i++)f[0][i]=i;
   for(int i=1;i<=la;i++){
   	for(int j=1;j<=lb;j++){
   		if(a[i]==b[j])f[i][j]=f[i-1][j-1];
   		else{
   			f[i][j]=min(f[i-1][j],f[i][j-1],f[i-1][j-1])+1;
   		}
   	}
   }
   cout<<f[la][lb];
   return 0;
}