WA in "Little elephant and bombs"

I don’t know why this code gives WA for LEBOMBS. Can’t get an input in which it fails. Please, somebody can help me?

for _ in range(int(input())):
N = int(input())
S = '0' + input() + '0'

count = 0
for i in range(1, N+1):
    if S[i-1] == '0' and S[i+1] == '0' and S[i] == '0':
        count += 1

Elegant solution, I wouldn’t have thought to do it that way.
I have tried to find a bug on my own, but wasn’t able to.
When looking trough accepted solutions I found the problem:


(where “_” denotes a space)
The problem is whitespace characters before or after the string, which get recognised as bombs
After fixing that issue you will get AC

Thank you very much, spaanse!!! You’re right! Finally got an AC with this solution!