import java.io.PrintWriter;
import java.io.BufferedReader;
import java.io.InputStreamReader;

/**
 * A program that reads integers and provides their prime factors.
 */
public class PrimeFactorization
{
  public static void main(String[] args)
    throws Exception
  {
    // Prepare for input and output.
    BufferedReader in = 
      new BufferedReader(new InputStreamReader(System.in));
    PrintWriter out = new PrintWriter(System.out, true);

    // Get input
    out.print("Enter a number and I will try to give you its prime factorization: ") ;
    out.flush() ;
    try // Input of an integer may fail
    {
      int num = Integer.parseInt(in.readLine()) ;
        if (num<=1) out.println ("Error: Does not compute.") ;
      else 
      {
        // Determine if num is prime.
 	double limit = Math.sqrt(num);
	boolean prime = true;
        for (int i=2 ; i <= limit && prime; i++) {
          if (num % i == 0) 
            prime = false;
        }
        if (prime) 
          out.println (num + " is prime.");
        else {
          out.print ("Prime factors are");
          int test = 2;
	  // Repeatedly divide number by possible factors until you
	  // know you can't divide it any more.
          while (num!=1)
          {
	    // If it's evenly divisible
            if (num % test == 0) {
	      // Remove all factors
              while (num % test == 0) 
                num = num / test;
	      // Print the factor
              out.print (" " + test);
            } //if
	    // Move on to the next factor
            test = test+1;
          } //while test
          out.println (".");
        }  // num is not prime
      } // num is not negative
    } //try
    catch (Exception e)
    {
      out.println ("That's not an integer.");
    }
  }// main
}// class