CodeEval - Max Range Sum - Easy

import sys

test_cases = open(sys.argv[1], 'r')
for test in test_cases:
    arr=test.split(";")
    valz=map(int,arr[1].split(" "))
    sum=0
    for i in range(int(arr[0])):
        sum = sum + valz[i]
    max=sum
    if max<0:
        max=0
    for i in range(int(arr[0]),len(valz)):
        sum = sum + valz[i]
        sum = sum - valz[i-int(arr[0])]
        if (max<sum):
            max=sum
    print max
test_cases.close()