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Problems

Subsequences Summing to Sevens

Subsequences Summing to Sevens

Farmer John's n cows are standing in a row, as they have a tendency to do from time to time. Each cow is labeled with a distinct integer ID number so FJ can tell them apart. FJ would like to take a photo of a contiguous group of cows but, due to a traumatic childhood incident involving the numbers 1 ... 6, he only wants to take a picture of a group of cows if their IDs add up to a multiple of 7. Help FJ determine the size of the largest group he can photograph.

Input

The first line contains n (1n50000). The next n lines each contain the n integer IDs of the cows (all are in the range 0 ... 106).

Output

Print the number of cows in the largest consecutive group whose IDs sum to a multiple of 7. If no such group exists, output 0.

Explanation

In this example 5 + 1 + 6 + 2 + 14 = 28.

Time limit 1 second
Memory limit 128 MiB
Input example #1
7
3
5
1
6
2
14
10
Output example #1
5
Source 2016 USACO January, Silver