#include <bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> P;
int INF = 3e18+7;
int mod = 1e9+7;
int dx[] = {1, 0,-1, 0, 1, 1,-1,-1};
int dy[] = {0, 1, 0,-1, 1,-1, 1,-1};
int gcd(int X,int Y) {
    if(X%Y == 0) {
        return Y;
    }
    else {
        return gcd(Y,X%Y);
    }
}
signed main() {
    int A,B,K;
    cin >> A >> B >> K;
    int l = 0,r = INF;
    int tmp = A*B/gcd(A,B);
    while (l+1 < r) {
        int mid = (l+r)/2;
        if(mid/A+mid/B-mid/tmp < K) {
            l = mid;
        }
        else {
            r = mid;
        }
    }
    cout << r << endl;
}