#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
using namespace std;

int main(){
	long long A,B,T;
	cin >> A >> B >> T;

	long long lb = ( T/(A+B) ) * (A+B);
	long long ub = (T/(A+B) +1) * (A+B);

	vector<long long> v;
	if(T <= lb) v.push_back(lb);
	v.push_back(ub);

	long long rem = T - lb;
	{
		long long x = lb + rem/A * A;
		long long y = lb + (rem/A+1) * A;

		if(T <= x) v.push_back(x);
		v.push_back(y);
	}
	{
		long long x = lb + rem/B * B;
		long long y = lb + (rem/B+1) * B;

		if(T <= x) v.push_back(x);
		v.push_back(y);
	}

	sort(v.begin(), v.end());
/*
	for(int i=0; i<v.size(); i++){
		cerr << v[i] << endl;
	}
*/
	cout << v[0] << endl;

	return 0;
}