National Olympiad in Informatics, China, 2013
The inner product (a.k.a. dot product) of two -dimensional vectors and is equal to the sum of products of their corresponding components. Specifically:
Given such -dimensional vectors, , Little Meow-Meow would like to know if there exist two vectors whose inner product is a multiple of . Please help her solve this problem.
Input Specification
The first line of input contains positive integers , , and ,
respectively representing the number of vectors, the number of
dimensions, and the number of which an inner product could be a
multiple.
The next lines each contains nonnegative integers. On the -th
of these lines, the -th integer represents , the -th
component of vector .
Output Specification
Output two integers, separated by a space.
If there exist two vectors and whose inner product is
an integer multiple of , then output their indices and .
If there are multiple answers, output any one of them.
If an answer does not exist, then output -1 -1
.
Sample Input
3 5 2
1 0 1 0 1
1 1 0 1 0
0 1 0 1 1
Sample Output
2 3
Explanation
Constraints
Test Case | ||||
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Problem translated to English by .
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