#include <bits/stdc++.h>
using namespace std;
int jinzhi(int x, int i) {
    int count = 0, sum = 0;
    while (x) {
        if (x % 10 >= i)
            return -1;
        count += x % 10 * pow(i, sum);
        x /= 10;
        sum++;
    }
    return count;
}
int main() {
    int q, p, r;
    cin >> q >> p >> r;
    int q2, p2, r2;
    for (int i = 2; i <= 16; i++) {
        q2 = jinzhi(q, i);
        p2 = jinzhi(p, i);
        r2 = jinzhi(r, i);
        if (q2 * p2 == r2) {
            cout << i << endl;
            return 0;
        }
    }
    cout << 0;
    return 0;
}