#include <bits/stdc++.h>

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

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
using namespace std;
typedef long long ll;
const ll INF = 1ll<<60;

int main() {
    ll A, B, T;
    cin >> A >> B >> T;
    if (A < B) swap(A, B);
    if (T / A < 30000000) {
        ll best = INF;
        for (ll i = 0; i*A <= T; i++) {
            ll rest = T-i*A;
            if (rest % B == 0) best = T;
            else best = min(best,(rest/B+1)*B+i*A);
        }
        cout << best << endl;
    } else {
        ll g = __gcd(A, B);
        ll best = (T/g)*g;
        if (best < T) best += g;
        cout << best << endl;
    }
    return 0;
}