#include<bits/stdc++.h>
using namespace std;
int main(){
    long long a,b,k;cin>>a>>b>>k;
    assert(1<=a&&a<=1000000000);
    assert(1<=b&&b<=1000000000);
    assert(1<=k&&k<=1000000000);
    long long ok=b*k,ng=0;
    while(ok-ng>1){
        long long md=(ok+ng)/2;
        long long t=md/b+md/a-md/(a*b/__gcd(a,b));
        if(t>=k)ok=md;else ng=md;
    }
    cout<<ok<<endl;
}