//#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;
 
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
	return (ull)rng() % B;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    ll a,b,k; cin >> a >> b >> k;
    ll lm=a*b/__gcd(a,b);
    ll L=0,R=1e18;
    while(R-L>1){
        ll mid=(L+R)/2;
        ll aa=mid/a+mid/b-mid/lm;
        if(aa<k){
            L=mid;
        }
        else{
            R=mid;
        }
    }
    cout << R << endl;
}