#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <cmath>

using namespace std;

int main() {
	int a, b, t;

	cin >> a >> b >> t;

	int big = max(a, b);
	int small = min(a, b);

	if (small == 1) {
		return t;
	}

	int pay_big, pay_small;
	int left;
	int ans = 2e9;
	for (int i = ceil(1.0 * t) / big; i >= 0; i--) {
		pay_big = i * big;
		left = t - pay_big;
		pay_small = ceil(1.0 * left / small) * small;
		ans = min(ans, pay_big + pay_small);
	}

	cout << ans << endl;
	return 0;
}