Consider a chess board with r rows and c columns, where every square contains between 0 and 9 coins. Supose that the upper-left square is white. For instance, this is an empty board with four rows and five columns:

showmover=false, label=false, maxfield=e4

Write a program such that, given a chess board, computes the total number of coins on its white squares.

Input

Input begins with the number of rows r and the number of columns c. Follow r lines, each one with c characters between ‘0’ and ‘9’.

Output

Print the total number of coins on the white squares of the board.

Public test cases

**Input**

3 4 2735 0479 1508

**Output**

19

**Input**

1 20 01234567890123456789

**Output**

40

**Input**

2 1 4 5

**Output**

4

Information

- Author
- Salvador Roura
- Language
- English
- Translator
- Salvador Roura
- Original language
- Catalan
- Other languages
- Catalan
- Official solutions
- C++ Java Python
- User solutions
- C C++ Java Python