#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <iostream>
#include <sstream>
#include <functional>
#include <map>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <list>
#include <numeric>
using namespace std;
const double PI = 3.14159265358979323846;
const double EPS = 1e-12;
const int INF = 1<<25;
typedef pair<int,int> P;
typedef long long ll;
typedef unsigned long long ull;


int main(){
	ll a, b, c;
	cin>>a>>b>>c;
	ll ra = (c+a-1)/a*a, rb = (c+b-1)/b*b;
	ll res = min(ra, rb);
	for(ll i = 1; i <= 100000; i++){
		ll c2 = c-i*b;
		if((c2+a-1)/a<0) break;
		res = min(res, (c2+a-1)/a*a+i*b);
	}
	cout<<res<<endl;

	return 0;
}