#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define str string
#define pb push_back
#define pf push_front
#define in insert
#define all(v) v.begin(),v.end()
const int sz=1000000,INF=1000000000;
using namespace std;
void solve()
{
ll n,m,num,num1,num2,cnt,ans;
cin>>n>>m;
vector<ll>nums,Nums;
for(int i=0;i<n;i++)
{
cin>>num;
nums.pb(num);
}
for(int i=0;i<m;i++)
{
Nums.clear();
cin>>num1>>num2;
for(int j=num1-1;j<num2;j++)
{
Nums.pb(nums[j]);
}
sort(all(Nums));
for(int j=num2-num1+1;j>=0;j--)
{
cnt=Nums.end()-lower_bound(all(Nums),j);
if(cnt==j)
{
ans=j;
break;
}
}
cout<<ans<<"\n";
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);cout.tie(nullptr);
ll t=1;
//cin>>t;
while(t--)
{
solve();
}
}
