Description

A rectangular array consists of digits $0$ to $9$. Digits $1$ to $9$ denote cells. Two positions belong to the same cell if, moving up, down, left, or right through positions with cell digits, they are connected. Given the array, count the number of cells.

Input Format

The first line contains two integers $n$ and $m$.

The next $n$ lines each contain a string of length $m$ consisting only of characters 0 to 9, representing the $n \times m$ matrix.

Output Format

Output a single integer, the number of cells.

4 10
0234500067
1034560500
2045600671
0000000089

4

Hint

Constraints

For $100\%$ of the testdata, $1 \le n, m \le 100$.

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