#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;
}