A rectangular field of size m× n contains mn square areas. Some of the areas are occupied by a determinated growing (tomatoes, carrots, etc.) that is identified by a natural number strictly positive. It is known that growings are grouped in different disjointed rectangles and that a growing always is separated of another one by areas without grownings, identify by the value 0.

Write a program that reads fields and prints the number of rectangular growings.

Input

Input consists in a sequence of fields. For each field, it is given two natural numbers m and n with m≥1 and n≥1 that represent the size of the field. Then, it is given m rows, each one with n natural numbers that represent the growing of the area. The fields follow the hypotheses described previously.

Output

For each fielf of the input, print in a line the number of rectangular growings.

Public test cases

**Input**

6 10 1 1 1 0 3 3 3 0 2 2 1 1 1 0 3 3 3 0 2 2 0 0 0 0 3 3 3 0 0 0 2 2 0 0 3 3 3 0 4 4 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 4 4 4 0 3 3 0 0 0 0 9 0 0 0 0

**Output**

7 1

Information

- Author
- Jordi Petit
- Language
- English
- Translator
- Carlos Molina
- Original language
- Catalan
- Other languages
- Catalan
- Official solutions
- C++
- User solutions
- C++ Python