content: package diplomas;
  
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.math.BigInteger;
  import java.util.Scanner;
  
  public class Diplomas {
      private static BigInteger maxwh (BigInteger w2, BigInteger h2) {
          if (w2.compareTo(h2) > 0) {
              return w2;
          } else return h2;
      }
  
      private static BigInteger maxd (BigInteger w1, BigInteger h1, BigInteger mid1) {
          return (mid1.divide(w1).multiply((mid1.divide(h1))));
      }
  
  
      public static void main(String[] args) throws IOException {
          Scanner sc = new Scanner(new FileReader("input.txt"));
          String[] numbersInput = sc.nextLine().split(" ");
          BigInteger w = new BigInteger(numbersInput[0]);
          BigInteger h = new BigInteger(numbersInput[1]);
          BigInteger n = new BigInteger(numbersInput[2]);
  
          BigInteger hi, lo, mid;
          hi = maxwh(w, h).multiply(n);
          lo = BigInteger.ZERO;
  
          while (hi.subtract(lo).compareTo(BigInteger.ONE) > 0) {
              mid = (hi.add(lo)).divide(BigInteger.TWO);
              if (maxd(w, h, mid).compareTo(n) < 0) {
                  lo = mid;
              } else {
                  hi = mid;
              }
          }
  
          PrintWriter out = new PrintWriter(System.out);
          out.println(hi);
          out.flush();
      }
  }