#include <iostream>
using namespace std;
long long gcd(long long a, long long b){
  if(a%b == 0)return b;
  else return gcd(b,a%b);
}
int main(){
  long long a,b,c;cin>>a>>b>>c;
  long long mn = 1;
  long long mx = 2000000000000000000;
  while(mx-mn > 1){
    long long ce = (mn+mx)/2;
    if(ce/a + ce/b - ce/((a*b)/gcd(a,b)) >= c){
      mx = ce;
    }else{
      mn = ce;
    }
  }
  cout << mx << endl;
}