//program to find edit distance between two strings.

string s;

cin>>s;

string t;

cin>>t;

int m = s.length();

int n = t.length();

int arr[m+1][n+1];

for(int i=0;i<=m;i++){

for(int j=0;j<=m;j++){

if(i==0){

arr[i][j] = j;

}else if(j==0){

arr[i][j] = i;

}else if(s[i]==t[j]){

arr[i][j] = arr[i-1][j-1];

}

else{

arr[i][j] = min(arr[i-1][j-1], min(arr[i-1][j], arr[i][j-1]));

arr[i][j] += 1;

}

}

}

cout<<arr[m][n]<<endl;

return 0;

}