#include<iostream>
using namespace std;
int gcd(int a,int b){return b?gcd(b,a%b):a;}
long A,B,K,L;
main()
{
	cin>>A>>B>>K;
	L=A/gcd(A,B)*B;
	long l=0,r=A*K;
	while(r-l>1)
	{
		long mid=(l+r)/2;
		long cnt=mid/A+mid/B-mid/L;
		if(cnt>=K)r=mid;
		else l=mid;
	}
	cout<<r<<endl;
}