#include <bits/stdc++.h>
#define endl '\n'
using namespace std;
const int BLOCK = 100;
const int N = 2e5 + 5;
const int Q = 2e5 + 5;
struct Query
{
int l, r, id;
bool operator < (const Query &other)
{
if (l / BLOCK == other.l / BLOCK)
{
if ((l / BLOCK) & 1)
{
return r < other.r;
}
return r > other.r;
}
return l < other.l;
}
};
int n, t;
int p[N];
Query queries[Q];
int ans[Q];
int times[N];
int all;
int curr;
void add(int x)
{
times[x]++;
if (x >= curr)
{
all++;
}
if (all - times[curr] > curr)
{
all -= times[curr];
curr++;
}
}
void rem(int x)
{
times[x]--;
if (x >= curr)
{
all--;
}
if (all < curr)
{
curr--;
all += times[curr];
}
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> t;
for (int i = 1; i <= n; i++)
{
cin >> p[i];
}
for (int i = 1; i <= t; i++)
{
cin >> queries[i].l >> queries[i].r;
queries[i].id = i;
}
sort(queries + 1, queries + t + 1);
int l = 1, r = 0;
for (int i = 1; i <= t; i++)
{
while (r < queries[i].r)
{
r++;
add(p[r]);
}
while (l > queries[i].l)
{
l--;
add(p[l]);
}
while (r > queries[i].r)
{
rem(p[r]);
r--;
}
while (l < queries[i].l)
{
rem(p[l]);
l++;
}
ans[queries[i].id] = curr;
}
for (int i = 1; i <= t; i++)
{
cout << ans[i] << endl;
}
return 0;
}
