#include <iostream>

using namespace std;
using ll=long long;

ll gcd(ll m,ll n){
    if(n==0) return m;
    return gcd(n,m%n);
}
ll lcm(ll x,ll y){
    return x*y/gcd(x,y);
}

int main(){
    ll a,b,c,k;
    cin>>a>>b>>k;
    c=lcm(a,b);
    ll ok=2e18;
    ll ng=0;

    while(ok-ng>1){
        ll cen=(ok+ng)/2;
        if(k<=cen/a+cen/b-cen/c) ok=cen;
        else ng=cen;
    }
    cout<<ok<<endl;

    return 0;
}