#include "bits/stdc++.h"
using namespace std;
#define task ""
#define ll long long
#define endl '\n'
#define fi first
#define se second
#define vall(a) (a).begin(), (a).end()
#define sze(a) (int)a.size()
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ep emplace_back
#define pb push_back
#define pf push_front
const ll mod = 1e9 + 7;
const int N = 2e5 + 5;
const ll oo = 1e18;
bool START;
int n, q;
pii a[N];
struct ST {
vector<int> st[N << 2];
void merge(int id) {
int i = 0, j = 0;
while(i < sze(st[id << 1]) && j < sze(st[id << 1 | 1])) {
if (st[id << 1][i] < st[id << 1 | 1][j]) {
st[id].pb(st[id << 1][i++]);
} else {
st[id].pb(st[id << 1 | 1][j++]);
}
}
while(i < sze(st[id << 1])) st[id].pb(st[id << 1][i++]);
while(j < sze(st[id << 1 | 1])) st[id].pb(st[id << 1 | 1][j++]);
}
void build(int id, int l, int r) {
if (l == r) {
st[id].pb(a[l].se);
return;
}
int mid = (l + r) >> 1;
build(id << 1, l, mid);
build(id << 1 | 1, mid + 1, r);
merge(id);
}
int get(int id, int l, int r, int u, int v, int k) {
if (l == r) return st[id].back();
int p = upper_bound(vall(st[id << 1]), v) - lower_bound(vall(st[id << 1]), u);
int mid = (l + r) >> 1;
if (p >= k) return get(id << 1, l, mid, u, v, k);
return get(id << 1 | 1, mid + 1, r, u, v, k - p);
}
} st;
int b[N];
bool check(int x, int l, int r) {
return b[st.get(1, 1, n, l, r, (r - l + 1) - x + 1)] >= x;
}
inline void solve() {
sort(a + 1, a + 1 + n);
st.build(1, 1, n);
while(q--) {
int L, R;
cin >> L >> R;
int l = 0, r = R - L + 1, ans = 0;
while(l <= r) {
int mid = (l + r) >> 1;
if (check(mid, L, R)) {
ans = mid;
l = mid + 1;
} else {
r = mid - 1;
}
}
cout << ans << endl;
}
}
inline void input() {
cin >> n >> q;
for (int i = 1; i <= n; ++i) {
cin >> a[i].fi;
b[i] = a[i].fi;
a[i].se = i;
}
return solve();
}
bool END;
int main() {
if(fopen(task ".inp", "r")) {
freopen(task ".inp", "r", stdin);
freopen(task ".out", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
input();
cerr << endl << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << 's' << endl;
cerr << "Memory: " << fabs ((&END - &START)) / 1048576.0 << "MB\n";
return 0;
}
