#! /usr/bin/env python # Factorize numbers.# The algorithm is not efficient, but easy to understand.# If there are large factors, it will take forever to find them,# because we try all odd numbers between 3 and sqrt(n)... import sysfrom math import sqrt error = 'fact.error'            # exception def fact(n):    if n < 1: raise error   # fact() argument should be >= 1    if n == 1: return []    # special case    res = []    # Treat even factors special, so we can use i = i+2 later    while n%2 == 0:        res.append(2)        n = n/2    # Try odd numbers up to sqrt(n)    limit = sqrt(float(n+1))    i = 3    while i <= limit:        if n%i == 0:            res.append(i)            n = n/i            limit = sqrt(n+1)        else:            i = i+2    if n != 1:        res.append(n)    return res def main():    if len(sys.argv) > 1:        for arg in sys.argv[1:]:            n = eval(arg)            print n, fact(n)    else:        try:            while 1:                n = input()                print n, fact(n)        except EOFError:            pass if __name__ == "__main__":    main()