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#3957

Subsequences Summing to Sevens 2s 512MB

Problems

Farmer John'sN 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 \ldots 6, he only wants to take a picture of a group of cows if their IDs add up to a multiple of 7.

Please help FJ determine the size of the largest group he can photograph.


Input

The first line of input contains N (1 \leq N \leq 50,000). The next N lines each contain the N integer IDs of the cows (all are in the range 0 \ldots 1,000,000).


Output

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

You may want to note that the sum of the IDs of a large group of cows might be too large to fit into a standard 32-bit integer. If you are summing up large groups of IDs, you may therefore want to use a larger integer data type, like a 64-bit "long long" in C/C++.


Example 

7 
3 
5 
1 
6
2 
14 
10 
5

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



Source

USACO 2016 January Silver

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