#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    int a, b, k;
    cin >> a >> b >> k;
    ll g = 1LL*a/__gcd(a, b)*b;
    ll ng = 0, ok = INF<ll>;
    while(ok-ng > 1){
        ll mid = (ok+ng)/2;
        if(mid/a+mid/b-mid/g >= k) ok = mid;
        else ng = mid;
    }
    cout << ok << "\n";
    return 0;
}