A thermal camera reports an R-by-C grid of integer temperatures. The readings are calibrated so that every row is sorted in non-increasing order from left to right, and every column is sorted in non-increasing order from top to bottom (so the warmest reading is at the top-left and the coldest at the bottom-right).

Count how many readings are strictly below zero (negative).

Input format

Line 1: two integers R and C. Next R lines: each contains C space-separated integers, forming a matrix that is non-increasing along every row and down every column.

Output format

A single integer: the number of negative readings.

Constraints

• 1 <= R, C <= 200
• -1000000000 <= each reading <= 1000000000
• Every row is non-increasing left to right; every column is non-increasing top to bottom.

3 3
4 3 1
2 0 -1
-2 -3 -5

4

2 2
5 3
2 1

0