#include <bits/stdc++.h>
#define TASK "coci2021_r6_index"
#define int long long
#define double long double
#define fi first
#define se second
#define pb push_back
#define ii pair<int, int>
#define vi vector<int>
#define vvi vector<vi>
#define vii vector<ii>
#define reset(f, x) memset(f, x, sizeof(f))
#define all(x) x.begin(), x.end()
#define sz(x) (long long)x.size()
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define FORV(v, H) for (auto &v: H)
#define __builtin_popcount __builtin_popcountll
#define BIT(mask, i) ((mask >> i) & 1ll)
#define MASK(i) (1ll << (i))
#define ONBIT(mask, i) (mask (1ll << (i)))
#define OFFBIT(mask, i) (mask &~ (1ll << (i)))
#define mid(l, r) ((l + r) >> 1)
#define left(id) (id << 1)
#define right(id) ((id << 1) 1)
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define UNIQUE(x) sort(all(x)); x.resize(distance(x.begin(), unique(all(x))))
#define BUG1(a) cout << a << '\n'
#define BUG2(a, b) cout << a << " " << b << '\n'
#define BUG3(a, b, c) cout << a << " " << b << " " << c << '\n'
#define BUG4(a, b, c, d) cout << a << " " << b << " " << c << " " << d << '\n'
#define BUG5(a, b, c, d, e) cout << a << " " << b << " " << c << " " << d << " " << e << '\n'
#define BUG6(a, b, c, d, e, f) cout << a << " " << b << " " << c << " " << d << " " << e << " " << f << '\n'
using namespace std;
template <class X, class Y> bool maximize(X &A, const Y &B){
if (A < B) return A = B, true;
return false;
}
template <class X, class Y> bool minimize(X &A, const Y &B){
if (A > B) return A = B, true;
return false;
}
const int oo = 1e18;
const int MOD = 1e9 + 7;
const int MAXN = 2e5 + 5;
const int LOG = 16;
const int base = 447;
const int BLOCK = 317;
const int dx[] = {0, 0, 1, 0, -1};
const int dy[] = {0, 1, 0, -1, 0};
int N, Q;
int a[MAXN], block[MAXN], bit[MAXN], res[MAXN], ans = 0;
struct Query{
int l, r, id;
} q[MAXN];
void add(int x, int y){
for(; x; x -= x & -x) bit[x] += y;
}
int get(int x){
int ans = 0;
for(; x < MAXN; x += x & -x) ans += bit[x];
return ans;
}
void Add(int x){
add(a[x], 1);
if (get(ans + 1) >= ans + 1) ans++;
}
void Remove(int x){
add(a[x], -1);
if (get(ans) < ans) ans--;
}
main(){
if (fopen(TASK".inp", "r")){
freopen(TASK".inp", "r", stdin);
freopen(TASK".out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> N >> Q;
FOR(i, 1, N) cin >> a[i];
FOR(i, 1, Q){
cin >> q[i].l >> q[i].r;
q[i].id = i;
}
FOR(i, 1, N) block[i] = (i - 1) / BLOCK;
sort(q + 1, q + Q + 1, [&](const Query &x, const Query &y){
if (block[x.l] != block[y.l]) return block[x.l] < block[y.l];
if (block[x.l] & 1) return x.r > y.r;
return x.r < y.r;
});
int l = 1, r = 0;
FOR(i, 1, Q){
while (r < q[i].r) Add(++r);
while (r > q[i].r) Remove(r--);
while (l < q[i].l) Remove(l++);
while (l > q[i].l) Add(--l);
res[q[i].id] = ans;
}
FOR(i, 1, Q) cout << res[i] << '\n';
return 0;
}
/*
___ __ ___ _______ ___ ___ ________ ___ ________ ___ ___ ___ ___ ___ ___
\ \\ \ |\ \|\ ___ \ |\ \|\ \ |\ ____\|\ \|\ __ \ |\ \|\ \|\ \|\ \ |\ \ / / |
\ \ \/ /|\ \ \ \ __/|\ \ \\\ \ \ \ \___|\ \ \ \ \|\ \ \ \ \\\ \ \ \\\ \ \ \ \/ / /
\ \ ___ \ \ \ \ \_|/_\ \ \\\ \ \ \ \ __\ \ \ \ __ \ \ \ __ \ \ \\\ \ \ \ / /
\ \ \\ \ \ \ \ \ \_|\ \ \ \\\ \ \ \ \|\ \ \ \ \ \ \ \ \ \ \ \ \ \ \\\ \ \/ / /
\ \__\\ \__\ \__\ \_______\ \_______\ \ \_______\ \__\ \__\ \__\ \ \__\ \__\ \_______\__/ / /
\|__| \|__|\|__|\|_______|\|_______| \|_______|\|__|\|__|\|__| \|__|\|__|\|_______|\___/ /
\|___|/
Author: Kieu Gia Huy a.k.a kiwi
From: C.H.V with luv <3
...
*/
