#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(const auto& (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define sar(a,n) {cout<<#a<<":";rep(pachico,n)cout<<" "<<a[pachico];cout<<endl;}

using namespace std;

template<typename S,typename T>auto&operator<<(ostream&o,pair<S,T>p){return o<<"{"<<p.fi<<","<<p.se<<"}";}
template<typename T>auto&operator<<(ostream&o,set<T>s){for(auto&e:s)o<<e<<" ";return o;}
template<typename S,typename T,typename U>
auto&operator<<(ostream&o,priority_queue<S,T,U>q){while(!q.empty())o<<q.top()<<" ",q.pop();return o;}
template<typename K,typename T>auto&operator<<(ostream&o,map<K,T>&m){for(auto&e:m)o<<e<<" ";return o;}
template<typename T>auto&operator<<(ostream&o,vector<T>v){for(auto&e:v)o<<e<<" ";return o;}
void ashow(){cout<<endl;}template<typename T,typename...A>void ashow(T t,A...a){cout<<t<<" ";ashow(a...);}
template<typename S,typename T,typename U>
struct TRI{S fi;T se;U th;TRI(){}TRI(S f,T s,U t):fi(f),se(s),th(t){}
bool operator<(const TRI&_)const{return(fi==_.fi)?((se==_.se)?(th<_.th):(se<_.se)):(fi<_.fi);}};
template<typename S,typename T,typename U>
auto&operator<<(ostream&o,TRI<S,T,U>&t){return o<<"{"<<t.fi<<","<<t.se<<","<<t.th<<"}";}

typedef pair<int, int> P;
typedef pair<ll,ll> pll;
typedef TRI<int, int, int> tri;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<P> vp;
typedef vector<string> vs;

const int MAX_VAL = 500005;
int a[MAX_VAL]; //要素
int cnt[MAX_VAL]; //区間内のiの個数
int res;        //区間内の種類の数

class Mo{
private:
    vector<int> left, right;
    const int width;
    void add(const int id);
    void del(const int id);

public:
    vector<int> ans;

    Mo(const int n) : width((int)sqrt(n)){}
    // クエリ[l,r)
    void insert(const int l, const int r){
        left.push_back(l), right.push_back(r);
    }
    void solve(){
        const int sz = (int)left.size();
        int nl = 0, nr = 0;
        vector<int> ord(sz);
        iota(ord.begin(), ord.end(), 0);
        sort(ord.begin(), ord.end(), [&](const int a, const int b){
            const int c = left[a] / width, d = left[b] / width;
            return (c == d) ? ((c & 1) ? (right[b] < right[a]) : (right[a] < right[b])) : (c < d);
        });
        ans.resize(sz);
        for(const int id : ord){
            while(nl > left[id]) add(--nl);
            while(nr < right[id]) add(nr++);  //add
            while(nl < left[id]) del(nl++);
            while(nr > right[id]) del(--nr);  //del
            ans[id] = res;
        }
    }
};

//idは元の配列のインデックス
void Mo::add(const int id)
{
    ++cnt[a[id]];
    if(cnt[a[id]] == 1) ++res;
}

void Mo::del(const int id)
{
    --cnt[a[id]];
    if(cnt[a[id]] == 0) --res;
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, q, l, r;
    cin >> n >> q;
    Mo mo(n);
    rep(i,n) cin >> a[i];
    rep(i,q){
        cin >> l >> r;
        --l, mo.insert(l, r);
    }
    mo.solve();
    const auto& ans = mo.ans;
    rep(i,q){
        cout << ans[i] << "\n";
    }
    return 0;
}

Measured memory_bytes: 15104