221_D. Little Elephant and Array
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
```python
import os
import sys
from io import BytesIO, IOBase
 
BUFSIZE = 8192
 
 
class FastIO(IOBase):
    newlines = 0
 
    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None
 
    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()
 
    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()
 
    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)
 
 
class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")
 
 
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")
#######################################
class query():
    global z
    def __init__(self,l,r,i):
        self.lb=(l-1)//z
        self.l=l
        self.r=r
        self.ind=i
    def __lt__(a,b):
        return (a.lb<b.lb or (a.lb==b.lb and a.r<b.r))
n,m=map(int,input().split())
a=list(map(int,input().split()))
for i in range(n):
    if a[i]>n:
        a[i]=-1
l1=[]
z=int(n**0.5)
for i in range(m):
    x,y=map(int,input().split())
    l1.append(query(x,y,i))
l1.sort()
d=[0]*(n+2)
l=1
r=0
ans=0
fans=[0]*m
for i in l1:
    while r<i.r:
        r+=1
        if d[a[r-1]]==a[r-1]:
            ans-=1
        d[a[r-1]]+=1
        if d[a[r-1]]==a[r-1]:
            ans+=1
    while l>i.l:
        l-=1
        if d[a[l-1]]==a[l-1]:
            ans-=1
        d[a[l-1]]+=1
        if d[a[l-1]]==a[l-1]:
            ans+=1
    while l<i.l:
        if d[a[l-1]]==a[l-1]:
            ans-=1
        d[a[l-1]]-=1
        if d[a[l-1]]==a[l-1]:
            ans+=1
        l+=1
    while r>i.r:
        if d[a[r-1]]==a[r-1]:
            ans-=1
        d[a[r-1]]-=1
        if d[a[r-1]]==a[r-1]:
            ans+=1
        r-=1
    fans[i.ind]=ans
for i in fans:
    print(i)

```