# PROBLEM LINK:

* Author:* Riddhish Lichade

*Prathamesh Sogale*

**Tester:***Ram Agrawal*

**Editorialist:**# DIFFICULTY:

CAKEWALK

# PREREQUISITES:

Arrays

# PROBLEM:

We are given with a 2-D array containing only 1s and 0s. The array represents the state of windows in flats of a building.1s represents the open window and 0 represents a closed window. Each flat has 2 windows. We have to find the number of empty flats. A flat is empty if both its windows are closed.

# EXPLANATION:

Traverse the given 2-D array. For each floor check 2 windows at a time. If both the elements are 0, then increment the counter by 1. Print the count at last

# SOLUTION:

## Setter's Solution

```
from sys import stdin
for _ in range(int(stdin.readline())):
n, f = map(int, stdin.readline().strip().split())
ans=0
for i in range(n):
l=list(map(int, stdin.readline().strip().split()))
i=0
while(i<f*2):
if(l[i]==0 and l[i+1]==0):
ans+=1
i+=2
print(ans)
```