Since Mr. DeMello hates flavour text, he decides to give you a sleek statement instead:
Given intervals of , answer queries.
Each query comes in the form
L_i R_i
, where you will check if you can move from to while always being on an interval (i.e., every integer on that interval must be contained in at least one of the intervals).Output
Y
if you can cover the range ; otherwise, outputN
if you cannot cover the range.
Can you help Mr. DeMello?
Constraints
Input Specification
The first line will contain two integers, and , the number of intervals and the number of queries, respectively.
The next lines will contain two integers, and , the endpoints of the interval.
The next lines will contain two integers, and , the endpoints of the query.
Output Specification
Output lines, the answers to the queries.
Sample Input
4 3
7 9
-5 4
10 14
16 19
8 10
-5 -5
11 18
Sample Output
Y
Y
N
Comments
Is there any overlaps in the intervals?