Problem3727--Little Elephant and Array

3727: Little Elephant and Array

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Time Limit : 2.000 sec  Memory Limit : 256 MiB

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Description

time limit per test
4 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

The Little Elephant loves playing with arrays. He has array a, consisting of n positive integers, indexed from 1 to n. Let's denote the number with index i as ai.

Additionally the Little Elephant has m queries to the array, each query is characterised by a pair of integers lj and rj (1≤lj≤rj≤n). For each query lj,rj the Little Elephant has to count, how many numbers x exist, such that number x occurs exactly x times among numbers alj,alj+1,...,arj.

Help the Little Elephant to count the answers to all queries.

Input

The first line contains two space-separated integers n and m (1≤n,m≤105) − the size of array a and the number of queries to it. The next line contains n space-separated positive integers a1, a2, ..., an (1≤ai≤109). Next m lines contain descriptions of queries, one per line. The j-th of these lines contains the description of the j-th query as two space-separated integers lj and rj (1≤lj≤rj≤n).

Output

In m lines print m integers − the answers to the queries. The j-th line should contain the answer to the j-th query.

Examples
Input
7 2
3 1 2 2 3 3 7
1 7
3 4
Output
3
1

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