import sys
input=sys.stdin.buffer.readline
class segtree():
    n=1
    size=1
    log=2
    d=[0]
    op=None
    e=10**15
    def __init__(self,V,OP,E):
        self.n=len(V)
        self.op=OP
        self.e=E
        self.log=(self.n-1).bit_length()
        self.size=1<<self.log
        self.d=[E for i in range(2*self.size)]
        for i in range(self.n):
            self.d[self.size+i]=V[i]
        for i in range(self.size-1,0,-1):
            self.update(i)
    def set(self,p,x):
        assert 0<=p and p<self.n
        p+=self.size
        self.d[p]=x
        for i in range(1,self.log+1):
            self.update(p>>i)
    def get(self,p):
        assert 0<=p and p<self.n
        return self.d[p+self.size]
    def prod(self,l,r):
        assert 0<=l and l<=r and r<=self.n
        sml=self.e
        smr=self.e
        l+=self.size
        r+=self.size
        while(l<r):
            if (l&1):
                sml=self.op(sml,self.d[l])
                l+=1
            if (r&1):
                smr=self.op(self.d[r-1],smr)
                r-=1
            l>>=1
            r>>=1
        return self.op(sml,smr)
    def all_prod(self):
        return self.d[1]
    def max_right(self,l,f):
        assert 0<=l and l<=self.n
        assert f(self.e)
        if l==self.n:
            return self.n
        l+=self.size
        sm=self.e
        while(1):
            while(l%2==0):
                l>>=1
            if not(f(self.op(sm,self.d[l]))):
                while(l<self.size):
                    l=2*l
                    if f(self.op(sm,self.d[l])):
                        sm=self.op(sm,self.d[l])
                        l+=1
                return l-self.size
            sm=self.op(sm,self.d[l])
            l+=1
            if (l&-l)==l:
                break
        return self.n
    def min_left(self,r,f):
        assert 0<=r and r<self.n
        assert f(self.e)
        if r==0:
            return 0
        r+=self.size
        sm=self.e
        while(1):
            r-=1
            while(r>1 & (r%2)):
                r>>=1
            if not(f(self.op(self.d[r],sm))):
                while(r<self.size):
                    r=(2*r+1)
                    if f(self.op(self.d[r],sm)):
                        sm=self.op(self.d[r],sm)
                        r-=1
                return r+1-self.size
            sm=self.op(self.d[r],sm)
            if (r& -r)==r:
                break
        return 0
    def update(self,k):
        self.d[k]=self.op(self.d[2*k],self.d[2*k+1])
    def __str__(self):
        return str([self.get(i) for i in range(self.n)])

from collections import deque
N,Q=map(int,input().split())
A=list(map(int,input().split()))
for i in range(N):
  A[i]-=1
X=[[] for i in range(N+1)]
for i in range(N):
  X[A[i]].append(i)
LR=[list(map(int,input().split())) for i in range(Q)]
Y=[[] for i in range(300000)]
for i in range(Q):
  LR[i][0]-=1
  Y[0].append(i)
que=deque([(0,N,0)])
C=0
def op(a,b):
  if a==ee:
    return b
  if b==ee:
    return a
  return (a[0]+b[0],max(b[1]+a[0],a[1]),max(a[2]+b[0],b[2]),max(a[3],b[3],a[2]+b[1],a[2],b[2],a[1],b[1]))

e0=(-1,-1,-1,-1)
e1=(1,1,1,1)
ee=(0,0,0,0)
seg=segtree([e0]*N,op,ee)
ANS=[0]*Q
while 1:
  v=que.popleft()
  l,r,k=v[0],v[1],v[2]
  if r==N:
    for i in range(N):
      seg.set(i,e0)
    C=0
  C+=1
  m=(l+r)>>1
  for i in range(m,r):
    for j in range(len(X[i])):
      seg.set(X[i][j],e1)
  if l+1==r:
    que.append((l,r,k*2+1))
    Y[k*2+1]=Y[k][:]
    for i in range(len(Y[k])):
      ANS[Y[k][i]]=r
    Y[k]=[]
    if C==N:
      break
    continue
  que.append((m,r,k*2+1))
  que.append((l,m,k*2+2))
  for i in range(len(Y[k])):
    ll,rr=LR[Y[k][i]][0],LR[Y[k][i]][1]
    v=seg.prod(ll,rr)
    if v[0]==ll-rr or v[0]-max(0,max(v[1],v[2],v[3])-1)<0:
      Y[k*2+2].append(Y[k][i])
    else:
      Y[k*2+1].append(Y[k][i])
  Y[k]=[]
  for i in range(l,m):
    for j in range(len(X[i])):
      seg.set(X[i][j],e1)
for i in range(Q):
  ANS[i]=str(ANS[i])
print('\n'.join(ANS))