Sample Input 1

3
-1 2 -1
2 2
1 -1 1

Sample Output 1

1

Sample Input 2

7
-1 4 5 1 0 -1 -1
-1 3 2 0 0 1
-1 4 -1 1 0 -1 -1
1 3 4 2 2 4
0 2 3 -1 4 4 2
-1 4 4 3 3 2
1 -1 -1 -1 4 2 -1

Sample Output 2

1

Sample Input 3

3
-1 2 -1
2 2
-1 -1 -1

Sample Output 3

4