#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll p, q, r;
ll f(ll t,ll n) {
	ll temp = 0,k = 1;
	while(n != 0) {
		temp += (n % 10) * k;
		k *= t;
		n /= 10;
	}
	return temp;
}
int main() {
	cin >> p >> q >> r;
	for(ll i = 2; i <= 16; i ++) {
		if(f(i, p) == -1 || f(i, q) == -1 || f(i, r) == -1) {
			break;
		}
		if(f(i, p) * f(i, q) == f(i, r)) {
			cout << i << " ";
			return 0;
		}
	}
	cout << 0 << "\n";
	return 0;
}