include <bits/stdc++.h>

long long a, b, s = 0, x, j, n;

cin >> a >> b;
x = a;
j = b;

while (a != b) 
{
    if (a > b)
        a = a - b;
    else
        b = b - a;
}
n = a;

a = x;
b = j;

for (int i = 1; i <= sqrt(n); i++) {
    if (a % i == 0) {
        if (b % i == 0) {
            x = 0;
            j = i;
            while (j != 0) 
            {
                x = x + j % 10;
                j = j / 10;
            }
            if (x > s) s = x;

            j = n / i;
            if (b % j == 0) {
                x = 0;
                while (j != 0) {
                    x = x + j % 10;
                    j = j / 10;
                }
                if (x > s) s = x;
            }
        }
    }
}

cout << s;
return 0;