import java.io.*; import java.util.*; import java.util.function.*; import java.util.stream.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int a = sc.nextInt(); int b = sc.nextInt(); int k = sc.nextInt(); long lcm = getLCM(a, b); long left = 1; long right = Long.MAX_VALUE / 2; while (right - left > 1) { long m = (left + right) / 2; long count = m / a + m / b - m / lcm; if (count < k) { left = m; } else { right = m; } } System.out.println(right); } static long getLCM(long a, long b) { return a / getGCD(a, b) * b; } static long getGCD(long a, long b) { if (b == 0) { return a; } else { return getGCD(b, a % b); } } } class Scanner { BufferedReader br; StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() { try { br = new BufferedReader(new InputStreamReader(System.in)); } catch (Exception e) { } } public int nextInt() { return Integer.parseInt(next()); } public long nextLong() { return Long.parseLong(next()); } public double nextDouble() { return Double.parseDouble(next()); } public String next() { try { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } } catch (Exception e) { e.printStackTrace(); } finally { return st.nextToken(); } } }