Задача 39250. Error

Given a sequence of N natural numbers. It is known that the sum of all numbers in the sequence does not exceed 10⁹. All its continuous subsequences are considered, in which the number of odd numbers is a multiple of K = 7. Find the largest sum of such a subsequence. 

Input
Given two input files (file A and file B), each containing in the first line, the number of numbers N (1 <= N <= 1,000,000). Each of the following N lines contains one natural number not exceeding 1000.

An example of the organization of source data in the input file (for К=4):
6
8
17
3
13
11
21

In this set, you can select the sequences 8+17+3+13+11 (sum 52) and 3+13+11+21 (sum 48). 
Answer(for K = 4): 52. 

Warning: do not use brute-force algorithm to process file B, which calculates the sum of all possible options, as the program written in such an algorithm will run too long.