시간 제한메모리 제한제출정답맞힌 사람정답 비율
1 초 128 MB3131238641.748%

문제

상근이는 정사각행렬에 0과 1을 쓰는 것을 좋아하는 아이이다. 오늘은 행렬에 플러스가 몇 개나 있는지 구해보려고 한다.

플러스는 변의 길이가 1보다 큰 홀수인 정사각형으로 가운데 행과 열은 1로, 나머지는 0으로 채워져 있다. 아래 행렬에는 플러스가 두 개 포함되어 있다.

00100 
00100 
11111 
00100 
00100 

행렬이 주어졌을 때, 플러스의 개수를 구하는 프로그램을 작성하시오.

입력

첫째 줄에 행렬의 크기 N이 주어진다. (3 ≤ N ≤ 2000) 다음 N개 줄에는 행렬이 주어진다.

출력

입력으로 주어진 행렬에 포함된 플러스의 개수를 출력한다.

예제 입력 1

5
00100
00100
11111
00100
00100

예제 출력 1

2

예제 입력 2

8
00010000
00010000
00010000
11111111
00010000
00010010
00010111
00010010

예제 출력 2

3
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