#include<bits/stdc++.h>
#define int long long
using namespace std;
int n, m, k, x;
bool check(int mid) {
	return (mid / n + mid / m - mid / x * 2) < k;
}
signed main() {
	scanf("%lld%lld%lld", &n, &m, &k);
	int l = 0, r = 5e8;
	x = n * m / __gcd(n, m);
	while(l <= r) {
		int mid = l + ((r - l) >> 1);
		if(check(mid)) l = mid + 1;
		else r = mid - 1;
	}
	printf("%lld", l);
	return 0;
}