public class Tools
{
    public static  int  gcd(int x, int y)
    {
        int k, min;
        int GCD = 1;    // Best GCD so far

        min = (x < y) ? x : y;

        for ( k = 2; k <= min; k++ )
        {
           if ( (x%k == 0) && (y%k == 0) )
              GCD = k; // a better GCD
        }
       
        return(GCD); // Return the GCD
    }
    
    
    public static boolean isNumberPrime(int num)
    {
      boolean isPrime = true;
      int i;

      for ( i = 2; i < num; i++ )
      {
          if ( num%i == 0 )
          {
             isPrime = false;
             break;
          }     
      }

      return(isPrime); // Return the value
    }
    
    
    public static boolean isWordPalindrome(String s)
    {
        boolean isPalindrome = true;
        int i, last;
      
        last = s.length() - 1;

        for ( i = 0; i < s.length()/2; i++ )
        {
            if ( s.charAt( i ) != s.charAt( last-i ) )
            {
                isPalindrome = false;
                break; // We can exit the loop now
            } 
        }

        return(isPalindrome); // Return the value
    }    
}