// yukicoder: No.176 2種類の切手
// 2019.5.11 bal4u

#include <stdio.h>

int gcd(int a, int b) {
	int r;
	while (b != 0) r = a % b, a = b, b = r;
	return a;
}

int main()
{
	int A, B, T, ans;

	scanf("%d%d%d", &A, &B, &T);
	if (A == 1 || T % A == 0 || T % B == 0) ans = T;
	else if (T <= A) ans = A;
	else if (T <= B) {
		ans = ((T-1)/A+1)*A;
		if (ans > B) ans = B;
	} else {
		int a, b, k, mi, g = gcd(A, B);
		long long t = (long long)A/g*B;
		if (T >= t) ans = (((T-t)-1)/g+1)*g;
		else {
			ans = 0x7fffffff;
			mi = A/g; if (T/B < mi) mi = T/B;
			for (b = 0; b <= mi; b++) {
				a = ((T-b*B)-1)/A+1;
				if ((k = a*A+b*B) < ans) ans = k;
			}
		}
	}
	printf("%d\n", ans);
	return 0;
}