#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
typedef pair<int, int> P;
const ll INF = LLONG_MAX;
//const int INF=INT_MAX;
//#define endl "\n"
ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; }
ll lcm(ll a, ll b){return a * b / gcd(a, b);}

int main(){
    ll a,b,k;
    cin>>a>>b>>k;
    ll n=lcm(a,b);
    ll l=0,r=INF;
    while(r-l>1){
        ll c=(l+r)/2;
        ll kazu=c/a+c/b-c/n;
        if(kazu<k)l=c;else r=c;
    }
    cout<<l+1<<endl;
    return 0;
}