import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.math.BigInteger;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		long a = Integer.parseInt(sa[0]);
		long b = Integer.parseInt(sa[1]);
		long k = Integer.parseInt(sa[2]);
		br.close();

		long c = lcm(a, b);
		long ok = a * k;
		long ng = 0;
		while (Math.abs(ok - ng) > 1) {
			long mid = (ok + ng) / 2;
			long aa = mid / a;
			long bb = mid / b;
			long cc = mid / c;
			if (aa + bb - cc >= k) {
				ok = mid;
			} else {
				ng = mid;
			}
		}
		System.out.println(ok);
	}

	static long lcm(long a, long b) {
		BigInteger ba = BigInteger.valueOf(a);
		BigInteger bb = BigInteger.valueOf(b);
		return ba.multiply(bb).divide(ba.gcd(bb)).longValue();
	}
}