#P3131. [USACO16JAN] Subsequences Summing to Sevens S
[USACO16JAN] Subsequences Summing to Sevens S
Description
Farmer John's 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 , 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 Format
The first line of input contains (). The next lines each contain the integer IDs of the cows (all are in the range ).
Output Format
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.
7
3
5
1
6
2
14
10
5
Hint
In this example, .
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