Subsquares in a matrix

Given an $n \times m$ matrix of numbers between 1 and 9, compute how many subsquares $3 \times 3$ 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 $n \times m$ 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 $3 \times 3$ that have all the numbers between 1 and 9.

Problem information

Author: Unknown
Translator: Salvador Roura

Generation: 2026-01-25T11:57:54.516Z