#!/usr/bin/env python
# -*- coding: utf-8 -*-
def 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 = 0
try: if int_or_exit(numlist[0]) > 0: maxsum = int_or_exit(numlist[0])
except IndexError: pass

itercycle = 1
for 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 += 1

print "Maximal sum is %d" % maxsum