#include <bits/stdc++.h>
template<class T> inline bool chmin(T&a, T b){if(a > b){a = b; return true;}else{return false;}}
template<class T> inline bool chmax(T&a, T b){if(a < b){a = b; return true;}else{return false;}}
#define ll long long
#define double long double
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=1;i<=(n);i++)
#define mod (ll)(1e9+7)
#define inf (ll)(3e18+7)
#define eps (double)(1e-9)
#define pi (double) acos(-1)
#define P pair<int,int>
#define PiP pair<int,pair<int,int>>
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
using namespace std;

ll gcd(ll a, ll b) {
	if (!b)return a;
	return gcd(b, a % b);
}

ll lcm(ll a, ll b) {
	return a / gcd(a, b) * b;
}

int main() {
    ll a, b, k;
    cin >> a >> b >> k;
    ll g = gcd(a, b);
    a /= g;
    b /= g;
    ll ok = inf, ng = 1;
    while(ok-ng > 1){
        ll mid = (ok + ng) / 2;
        ll cnt = mid/a+mid/b-mid/(a*b);
        if(cnt >= k)ok = mid;
        else ng = mid;
    }
    cout << ok * g << endl;
}