#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <algorithm>
#include <cmath>
#include <string>

using namespace std;

typedef vector <int> VI;
typedef vector <VI> VVI;
typedef vector <VVI> VVVI;
typedef vector <string> VS;
typedef pair<int,int> PII;
typedef long long LL;
typedef unsigned long long ULL;

#define each(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); i++)
#define sort(c) sort((c).begin(),(c).end())

#define range(i,a,b) for(int i=(a); i < (b); i++)
#define rep(i,n) range(i,0,n)

int main(){
	LL A,B,T;
	LL tmp, min_num;
	VI cand, dp, tmp_dp;
	cin >> A >> B >> T;
	if(A < T) dp.push_back(A);
	else cand.push_back(A);
	if(B < T) dp.push_back(B);
	else cand.push_back(B);
	while(dp.size() != 0){
		each(i, dp){
			tmp = *i + A;
			if(tmp < T) tmp_dp.push_back(tmp);
			else cand.push_back(tmp);
			tmp = *i + B;
			if(tmp < T) tmp_dp.push_back(tmp);
			else cand.push_back(tmp);
		}
		dp = tmp_dp;
		tmp_dp.clear();
	}
	min_num = cand[0];
	each(i, cand){
		if(*i < min_num) min_num = *i;
	}
	cout << min_num << endl;
	return 0;
}