num = int( input( "Enter a number: " ) )
mult1 = 1
mult2 = 2
mult3 = 3

if num > 1 :
    while mult1 <= num :
        mult1 = mult1 + 1

        if mult1 * mult2 == num :
            mult1 = num + 1
            print()
            print( num, "is not a prime number" )

        if mult1 * mult3 == num :
            mult1 = num + 1
            print()
            print( num, "is not a prime number" )

        elif mult1 == num :
            print()
            print( num, "is a prime number" )

else :
    print( "1 is not a prime number" )