#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<int(n); ++i)
#define repll(i,m,n) for(ll i=m; i<ll(n); ++i)
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define fi first
#define se second

template<typename T> bool chmin(T& a, T b){ if(a > b){a = b; return true;} return false; }
template<typename T> bool chmax(T& a, T b){ if(a < b){a = b; return true;} return false; }

template<typename T> T gcd(T a, T b){ return a % b ? gcd(b, a % b) : b; }
template<typename T> T lcm(T a, T b){ return a / gcd(a, b) * b; }

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    ll A, B, K;
    cin >> A >> B >> K;

    ll L = lcm(A, B);
    ll high = 1e18 + 100, low = 1LL;
    while(abs(high - low) > 1){
        ll mid = (high + low) / 2;
        if(mid / A + mid / B - mid / L >= K) high = mid;
        else low = mid;
    }
    cout << high << endl;

    return 0;
}