Mumatrix
Medium
Execution time limit is 2 seconds
Runtime memory usage limit is 256 megabytes
The binary matrix is given. Find its square modulo 2.
Input
The first line contains the size of the matrix n (1 ≤ n ≤ 4000). Each of the next n lines contains n symbols, equal to 0 or 1.
Output
Print one number - the amount of ones in a square matrix.
Examples
Input #1
Answer #1
Submissions 547
Acceptance rate 22%