Stuff

#!/usr/bin/env python# -*- coding: utf-8 -*-from osdef int_or_exit(num):    try: return int(num)    except ValueError:        print "Malformed input.txt"        exit()def read_or_exit(filename):    try: return open(filename, "r")    except IOError:        print "Cannot open input.txt. Does it exist?"        exit()fin = read_or_exit("input.txt")numlist = fin.read().split()numcount = len(numlist)maxsum = int_or_exit(numlist[0])itercycle = 1for num in numlist:    newsum = int_or_exit(num)    if newsum > maxsum: maxsum = newsum    for numx in numlist[itercycle:]:        newsum += int_or_exit(numx)        if newsum > maxsum: maxsum = newsum    itercycle += 1print "Maximal sum is %d" % maxsum