#include <iostream>
using namespace std;
int main(void) {
	unsigned long long 
		a, b, c,
		ng = -1, ok = 1LL << 60;
	cin >> a >> b >> c;
	while (ok - ng > 1) {
		unsigned long long
			mid = (ok + ng) / 2,
			key = (mid / a * b) + (mid - mid / a);
		if (key >= c) ok = mid;
		else ng = mid;
	}
	cout << ok << endl;
	return 0;
}