#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using PLL = pair<ll, ll>;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define repn(i,n) for(int i = 0; i <= (int)(n); i++)
#define srep(i,l,n) for(int i = l; i < (int)(n); i++)
#define srepn(i,l,n) for(int i = l; i <= (int)(n); i++)
#define drep(i,n) for(int i = (int)(n-1); i >= 0; i--)
#define drepn(i,n) for(int i = (int)(n); i >= 0; i--)
#define debug(var)  do{std::cout << #var << " : ";view(var);}while(0)
template<typename T> void view(T e){std::cout << e << std::endl;}
template<typename T> void view(const std::vector<T>& v){for(const auto& e : v){ std::cout << e << " "; } std::cout << std::endl;}
template<typename T> void view(const std::vector<std::vector<T> >& vv){ for(const auto& v : vv){ view(v); } }
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<class T> T gcd(T a, T b) {if(b==0)return a; else return gcd(b,a%b);}
template<class T> T lcm(T a, T b) {return a/gcd(a,b)*b;}
template<class T = int> using V = vector<T>;
template<class T = int> using VV = vector<V<T>>;
bool isIn(int i, int j, int h, int w) {return i >= 0 && i < h && j >= 0 && j < w;}
void Yes(){cout << "Yes" << endl;}
void No(){cout << "No" << endl;}
void YES(){cout << "YES" << endl;}
void NO(){cout << "NO" << endl;}
void err() {cout << -1 << endl;}
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pb push_back
#define ep emplace_back

const int MOD = 1000000007;
const int INF = 1e9;

#define PI acos(-1);
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,1,-1};
int ddx[8] = {1,1,1,-1,-1,-1,0,0};
int ddy[8] = {0,1,-1,0,1,-1,1,-1};

template <class Abel> struct BIT {
    vector<Abel> dat[2];
    Abel UNITY_SUM = 0;                     // to be set
    
    /* [1, n] */
    BIT(int n) { init(n); }
    void init(int n) { for (int iter = 0; iter < 2; ++iter) dat[iter].assign(n + 1, UNITY_SUM); }
    
    /* a, b are 1-indexed, [a, b) */
    inline void sub_add(int p, int a, Abel x) {
        for (int i = a; i < (int)dat[p].size(); i += i & -i)
            dat[p][i] = dat[p][i] + x;
    }
    inline void add(int a, int b, Abel x) {
        sub_add(0, a, x * -(a - 1)); sub_add(1, a, x); sub_add(0, b, x * (b - 1)); sub_add(1, b, x * (-1));
    }
    
    /* a is 1-indexed, [a, b) */
    inline Abel sub_sum(int p, int a) {
        Abel res = UNITY_SUM;
        for (int i = a; i > 0; i -= i & -i) res = res + dat[p][i];
        return res;
    }
    inline Abel sum(int a, int b) {
        return sub_sum(0, b - 1) + sub_sum(1, b - 1) * (b - 1) - sub_sum(0, a - 1) - sub_sum(1, a - 1) * (a - 1);
    }
    
    /* debug */
    void print() {
        for (int i = 1; i < (int)dat[0].size(); ++i) cout << sum(i, i + 1) << ",";
        cout << endl;
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, q;
    cin >> n >> q;
    V<> c(n);
    for(int i = 0; i < n; i++) cin >> c[i];
    vector<int> l(q), r(q), id(q);
    for(int i = 0; i < q; i++) {
        cin >> l[i] >> r[i];
        l[i]--;
        id[i] = i;
    }
    sort(all(id), [&](int i, int j) {return r[i] < r[j];});
    BIT<int> bit(n + 3);
    vector<int> pre(5e5 + 5, -1);
    vector<int> ans(q, 0);
    int R = 0;
    for(auto i : id) {
        for(; R < r[i]; ++R) {
            bit.add(pre[c[R]] + 2, R + 2, 1);
            pre[c[R]] = R;
        }
        int tmp = bit.sum(l[i] + 1, l[i] + 2);
        ans[i] = max(ans[i], tmp);
    }
    for(int i = 0; i < q; i++) {
        printf("%d\n", ans[i]);
    }
}

Measured memory_bytes: 19452