use std::io::*;

fn gcd(a: u64, b: u64) -> u64 {
    if b == 0 {
        return a;
    }
    gcd(b, a % b)
}

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let a: u64 = itr.next().unwrap().parse().unwrap();
    let b: u64 = itr.next().unwrap().parse().unwrap();
    let k: u64 = itr.next().unwrap().parse().unwrap();
    let l = a / gcd(a, b) * b;

    let mut ok = a * k;
    let mut ng = 0;
    while ok - ng > 1 {
        let mid = (ok + ng) >> 1;
        let cnt = mid / a + mid / b - mid / l;
        if cnt >= k {
            ok = mid;
        } else {
            ng = mid;
        }
    }
    println!("{}", ok);
}