C. Ladder
time limit per test
2 seconds
memory limit per test
256 megabytes
standard input
standard output

You've got an array, consisting of n integers a 1, a 2, ..., a n. Also, you've got m queries, the i-th query is described by two integers l i, r i. Numbers l i, r i define a subsegment of the original array, that is, the sequence of numbers a l i, a l i + 1, a l i + 2, ..., a r i. For each query you should check whether the corresponding segment is a ladder.

A ladder is a sequence of integers b 1, b 2, ..., b k, such that it first doesn't decrease, then doesn't increase. In other words, there is such integer x (1 ≤ x ≤ k), that the following inequation fulfills: b 1 ≤ b 2 ≤ ... ≤ b x ≥ b x + 1 ≥ b x + 2... ≥ b k. Note that the non-decreasing and the non-increasing sequences are also considered ladders.


The first line contains two integers n and m (1 ≤ n, m ≤ 105) — the number of array elements and the number of queries. The second line contains the sequence of integers a 1, a 2, ..., a n (1 ≤ a i ≤ 109), where number a i stands for the i-th array element.

The following m lines contain the description of the queries. The i-th line contains the description of the i-th query, consisting of two integers l i, r i (1 ≤ l i ≤ r i ≤ n) — the boundaries of the subsegment of the initial array.

The numbers in the lines are separated by single spaces.


Print m lines, in the i-th line print word "Yes" (without the quotes), if the subsegment that corresponds to the i-th query is the ladder, or word "No" (without the quotes) otherwise.

8 6
1 2 1 3 3 5 2 1
1 3
2 3
2 4
8 8
1 4
5 8