#include <bits/stdc++.h>
using namespace std;
const int MAX = 2e5 + 10;
vector<int> P(MAX);
struct node {
int l, r, m;
vector<int> v;
node *lc, *rc;
node(int _l, int _r): l(_l), r(_r), m((_l + _r) >> 1) {
if (l == r) {
v.push_back(P[l]);
} else {
lc = new node(l, m);
rc = new node(m + 1, r);
v.resize(lc -> v.size() + rc -> v.size());
auto lv = lc -> v.begin(), rv = rc -> v.begin(), it = v.begin();
while (lv != lc -> v.end() && rv != rc -> v.end()) *(it++) = *((*lv < *rv ? lv : rv)++);
while (lv != lc -> v.end()) *(it++) = *(lv++);
while (rv != rc -> v.end()) *(it++) = *(rv++);
}
}
int query(int _l, int _r, int _v) {
if (l == _l && r == _r) return (int) (v.end() - lower_bound(v.begin(), v.end(), _v));
if (_r <= m) return lc -> query(_l, _r, _v);
if (_l > m) return rc -> query(_l, _r, _v);
return lc -> query(_l, m, _v) + rc -> query(m + 1, _r, _v);
}
} *root;
int main() {
int N, Q, L, R, l, r, m, ans;
cin >> N >> Q;
for (int i = 1; i <= N; i++) cin >> P[i];
root = new node(1, N);
while (Q--) {
cin >> L >> R;
l = 1, r = R - L + 1;
while (l <= r) {
m = (l + r) >> 1;
if (root -> query(L, R, m) >= m) {
ans = m;
l = ++m;
} else {
r = --m;
}
}
cout << ans << '\n';
}
}
