import java.io.*; import java.util.*; import java.util.stream.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); long a = sc.nextInt(); long b = sc.nextInt(); int n = sc.nextInt(); long lcm = getLCM(a, b); long left = 0; long right = Long.MAX_VALUE / 10; while (right - left > 1) { long m = (left + right) / 2; long count = m / a + m / b - m / lcm; if (count >= n) { right = m; } else { left = m; } } System.out.println(right); } static long getLCM(long x, long y) { return x / getGCD(x, y) * y; } static long getGCD(long x, long y) { if (y == 0) { return x; } else { return getGCD(y, x % y); } } } class Utilities { static String arrayToLineString(Object[] arr) { return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n")); } static String arrayToLineString(int[] arr) { return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new)); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public int[] nextIntArray() throws Exception { return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray(); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }