N people wants to sit there is a line with length K containe some available seats,they want to know if they can find consecutive seats available to sit .

Input Format

first line contain K and N

the length of the line : K

number of people : N

second line contain string

string represent the seats 0 mean this seat is available , 1 mean this seat is already taken .

Constraints

1<=N,k<=10^5

Output Format

print YES if they can find a place to set otherwise print NO

Sample Input 0

5 2 10101 

Sample Output 0

NO 

Sample Input 1

6 3 000011 

Sample Output 1

YES 

Sample Input 2

5 4 00100 

Sample Output 2

NO

please in c++ or python

doesn't matter