def maxSum(p, n):
sum_max = p[0]
sum_sum = 0
for i in range(0, n):
if sum_sum >= 0:
sum_sum += p[i]
else:
sum_sum = p[i]
if sum_sum > sum_max:
sum_max = sum_sum
return sum_max
p = (-1, -2, 5, -1, 2, -4)
print maxSum(p, 6)