Let a_1, …, a_n be an array of n positive integers. In one operation, you can choose an index i such that a_i = i, and remove a_i from the array (after the removal, the remaining parts are concatenated).

The weight of a is defined as the maximum number of elements you can remove.

You must answer q independent queries (x, y): after replacing the x first elements of a and the y last elements of a by n+1 (making them impossible to remove), what would be the weight of a?

Input

The first line contains two integers n and q (1 ≤ n, q ≤ 3 ⋅ 10^5) — the length of the array and the number of queries.

The second line contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ n) — elements of the array.

The i-th of the next q lines contains two integers x and y (x, y ≥ 0 and x+y < n).

Output

Print q lines, i-th line should contain a single integer — the answer to the i-th query.

Examples

Input


13 5
2 2 3 9 5 4 6 5 7 8 3 11 13
3 1
0 0
2 4
5 0
0 12


Output


5
11
6
1
0


Input


5 2
1 4 1 2 4
0 0
1 0


Output


2
0

Note

Explanation of the first query:

After making first x = 3 and last y = 1 elements impossible to remove, a becomes [×, ×, ×, 9, 5, 4, 6, 5, 7, 8, 3, 11, ×] (we represent 14 as × for clarity).

Here is a strategy that removes 5 elements (the element removed is colored in red):

  * [×, ×, ×, 9, \color{red}{5}, 4, 6, 5, 7, 8, 3, 11, ×] 
  * [×, ×, ×, 9, 4, 6, 5, 7, 8, 3, \color{red}{11}, ×] 
  * [×, ×, ×, 9, 4, \color{red}{6}, 5, 7, 8, 3, ×] 
  * [×, ×, ×, 9, 4, 5, 7, \color{red}{8}, 3, ×] 
  * [×, ×, ×, 9, 4, 5, \color{red}{7}, 3, ×] 
  * [×, ×, ×, 9, 4, 5, 3, ×] (final state) 



It is impossible to remove more than 5 elements, hence the weight is 5.
from bisect import *
from collections import *
from math import gcd,ceil,sqrt,floor,inf
from heapq import *
from itertools import *
from operator import add,mul,sub,xor,truediv,floordiv
from functools import *

#------------------------------------------------------------------------
import os
import sys
from io import BytesIO, IOBase
# region fastio

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")


#------------------------------------------------------------------------
def RL(): return map(int, sys.stdin.readline().rstrip().split())
def RLL(): return list(map(int, sys.stdin.readline().rstrip().split()))
def N(): return int(input())
#------------------------------------------------------------------------

from types import GeneratorType
 
 
def bootstrap(f, stack=[]):
    def wrappedfunc(*args, **kwargs):
        if stack:
            return f(*args, **kwargs)
        else:
            to = f(*args, **kwargs)
            while True:
                if type(to) is GeneratorType:
                    stack.append(to)
                    to = next(to)
                else:
                    stack.pop()
                    if not stack:
                        break
                    to = stack[-1].send(to)
            return to
 
    return wrappedfunc


farr=[1]
ifa=[]

def fact(x,mod=0):
    if mod:
        while x>=len(farr):
            farr.append(farr[-1]*len(farr)%mod)
    else:
        while x>=len(farr):
            farr.append(farr[-1]*len(farr))
    return farr[x]

def ifact(x,mod):
    global ifa
    ifa.append(pow(farr[-1],mod-2,mod))
    for i in range(x,0,-1):
        ifa.append(ifa[-1]*i%mod)
    ifa=ifa[::-1]

def per(i,j,mod=0):
    if i<j: return 0
    if not mod:
        return fact(i)//fact(i-j)
    return farr[i]*ifa[i-j]%mod
    
def com(i,j,mod=0):
    if i<j: return 0
    if not mod:        
        return per(i,j)//fact(j)
    return per(i,j,mod)*ifa[j]%mod

def catalan(n):
    return com(2*n,n)//(n+1)
    
def linc(f,t,l,r):
    while l<r:
        mid=(l+r)//2
        if t>f(mid):
            l=mid+1
        else:
            r=mid
    return l

def rinc(f,t,l,r):
    while l<r:
        mid=(l+r+1)//2
        if t<f(mid):
            r=mid-1
        else:
            l=mid
    return l

def ldec(f,t,l,r):
    while l<r:
        mid=(l+r)//2
        if t<f(mid):
            l=mid+1
        else:
            r=mid
    return l

def rdec(f,t,l,r):
    while l<r:
        mid=(l+r+1)//2
        if t>f(mid):
            r=mid-1
        else:
            l=mid
    return l

def isprime(n):
    for i in range(2,int(n**0.5)+1):
        if n%i==0:
            return False
    return True

def binfun(x):
    c=0
    for w in arr:
        c+=ceil(w/x)
    return c

def lowbit(n):
    return n&-n

def inverse(a,m):
    a%=m
    if a<=1: return a
    return ((1-inverse(m,a)*m)//a)%m

class BIT:
    def __init__(self,arr):
        self.arr=arr
        self.n=len(arr)-1
        
    def update(self,x,v):
        while x<=self.n:
            self.arr[x]+=v
            x+=x&-x

    def query(self,x):
        ans=0
        while x:
            ans+=self.arr[x]
            x&=x-1
        return ans

class smt:
    def __init__(self,l,r,arr):
        self.l=l
        self.r=r
        self.value=(1<<31)-1 if l<r else arr[l]
        mid=(l+r)//2
        if(l<r):
            self.left=smt(l,mid,arr)
            self.right=smt(mid+1,r,arr)
            self.value&=self.left.value&self.right.value
        #print(l,r,self.value)
    def setvalue(self,x,val):
        if(self.l==self.r):
            self.value=val
            return
        mid=(self.l+self.r)//2
        if(x<=mid):
            self.left.setvalue(x,val)
        else:
            self.right.setvalue(x,val)
        self.value=self.left.value&self.right.value
    def ask(self,l,r):
        if(l<=self.l and r>=self.r):
            return self.value
        val=(1<<31)-1
        mid=(self.l+self.r)//2
        if(l<=mid):
            val&=self.left.ask(l,r)
        if(r>mid):
            val&=self.right.ask(l,r)
        return val

class DSU:#容量+路径压缩
    def __init__(self,n):
        self.c=[-1]*n

    def same(self,x,y):
        return self.find(x)==self.find(y)

    def find(self,x):
        if self.c[x]<0:
            return x
        self.c[x]=self.find(self.c[x])
        return self.c[x]

    def union(self,u,v):
        u,v=self.find(u),self.find(v)
        if u==v:
            return False
        if self.c[u]<self.c[v]:
            u,v=v,u
        self.c[u]+=self.c[v]
        self.c[v]=u
        return True

    def size(self,x): return -self.c[self.find(x)]
    
class UFS:#秩+路径
    def __init__(self,n):
        self.parent=[i for i in range(n)]
        self.ranks=[0]*n

    def find(self,x):
        if x!=self.parent[x]:
            self.parent[x]=self.find(self.parent[x])
        return self.parent[x]

    def union(self,u,v):
        pu,pv=self.find(u),self.find(v)
        if pu==pv:
            return False
        if self.ranks[pu]>=self.ranks[pv]:
            self.parent[pv]=pu
            if self.ranks[pv]==self.ranks[pu]:
                self.ranks[pu]+=1
        else:
            self.parent[pu]=pv

def Prime(n):
    c=0
    prime=[]
    flag=[0]*(n+1)
    for i in range(2,n+1):
        if not flag[i]:
            prime.append(i)
            c+=1
        for j in range(c):
            if i*prime[j]>n: break
            flag[i*prime[j]]=prime[j]
            if i%prime[j]==0: break
    return prime

def dij(s,graph):
    d={}
    d[s]=0
    heap=[(0,s)]
    seen=set()
    while heap:
        dis,u=heappop(heap)
        if u in seen:
            continue
        for v in graph[u]:
            if v not in d or d[v]>d[u]+graph[u][v]:
                d[v]=d[u]+graph[u][v]
                heappush(heap,(d[v],v))
    return d

def GP(it): return [(ch,len(list(g))) for ch,g in groupby(it)]

class DLN:
    def __init__(self,val):
        self.val=val
        self.pre=None
        self.next=None
        


t=1
for i in range(t):
    n,q=RL()
    a=RLL()
    a=[i+1-a[i] for i in range(n)]
    ans=[0]*q
    res=[[] for i in range(1+n)]
    for i in range(q):
        x,y=RL()
        l,r=x+1,n-y
        res[r].append((i,l))
    #print(a)
    bi=BIT([0]*(n+1))
    for r in range(1,n+1):
        if a[r-1]>=0:
            lo,hi=0,r
            while lo<hi:
                mid=(lo+hi+1)//2
                tmp=bi.query(n-mid+1)
                if tmp>=a[r-1]:
                    lo=mid
                else:
                    hi=mid-1
            if lo:
                bi.update(n-lo+1,1)
        for i,l in res[r]:
            ans[i]=bi.query(n-l+1)
        #print(r,ans,bi.arr)
    for x in ans:
        print(x)
        
                       
''' 
sys.setrecursionlimit(200000)
import threading
threading.stack_size(10**8)
t=threading.Thread(target=main)
t.start()
t.join()
'''
