#include<iostream>
#include<cmath>

using namespace std;

void ans(long long p, long long q, long long r)
{

	for (int i = 2;i <= 16;i++)
	{
		long long p_1 = p, q_1 = q, cnt_p = 0, cnt_q = 0, j = 0;

		while (p_1)
		{
			cnt_p += (p_1 % 10) * pow(i, j);

			p_1 /= 10;

			j++;
		}

		j = 0;

		while (q_1)
		{
			cnt_q += (q_1 % 10) * pow(i, j);

			q_1 /= 10;

			j++;
		}

		j = 0;

		long long cnt = 0, cnt_1 = cnt_p * cnt_q;

		while (cnt_1)
		{
			cnt += (cnt_1 % i) * pow(10, j);

			cnt_1 /= i;

			j++;
		}

		if (cnt == r)
		{
			cout << i << endl;

			exit(0);
		}
	}

	puts("0");
}

int main()
{
	long long p, q, r;

	cin >> p >> q >> r;

	ans(p, q, r);
}