Subsquares in a matrix X33408


Statement
 

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Given an n × m matrix of numbers between 1 and 9, compute how many subsquares 3 × 3 it has with all the numbers between 1 and 9.

Input

Input consists of several cases. Every case begins with n and m, followed by an n × m matrix of integer numbers between 1 and 9. Suppose that n and m are between 3 and 100.

Output

For every matrix, print the number of subsquares 3 × 3 that have all the numbers between 1 and 9.

Public test cases

  • Input

    3 4
1 2 3 4
5 6 7 8
9 8 4 8

3 3
1 1 1
1 1 1
1 1 1

4 4
1 2 3 7
4 5 6 4
7 8 9 1
1 2 3 7

    Output

    1
0
4
    • Information
    Author
    Salvador Roura
    Language
    English
    Official solutions
    Python
    User solutions
    Python