SP8917 PLUSEVI - How Many Plusses

Mirko is a strange boy so he has written down a square matrix full of ones and zeroes. Now he is interested in how many plusses there are in his matrix. A plus is a square such that its side has an odd length greater than 1 and all of its cells are zero, except for the middle row and the middle column: they must be full of ones. For example, in the matrix below there are two plusses, one inside the other: 00100 00100 11111 00100 00100

In the first line there is an integer N The next N lines are the rows of the matrix.

Print the number of plusses appearing in the matrix.