#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

#define REP(i,k,n) for(int i=k;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)

using namespace std;

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

	if(a < b) swap(a,b);

	int d = a-b;
	int res = 0;
	while(res < t)
	{
		if(res + a <= t) res += a;
		else res += b;
	}

	bool flag = true;
	while(flag)
	{
		if(res - d >= t) res -= d;
		else flag = false;
	}

	cout << res << endl;



	return 0;
}