#include <iostream>
using namespace std;

int main()
{
int A, B;
cin >> A >> B;

int res = 0;

while(A > 0 and B > 0) {
int cifra1 = A % 10;
int cifra2 = B % 10;

int plus = abs(cifra2 - cifra1);
int minus = cifra1 + (10 - cifra2);
int minus2 = (10 - cifra1) + cifra2;

res += min(plus, min(minus, minus2));


A /= 10;
B /= 10;
}

cout << res << endl;

return 0;
}