#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
#include<ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;

#define endl            "\n"
#define forn(i,x,n)     for(int i=x; i<n; i++)
#define forit(it, m)    for(decltype(m)::iterator it = m.begin(); it!=m.end(); ++it)
#define ff              first
#define ss              second
#define int             long long
#define pb              push_back
#define mp              make_pair
#define pii             pair<int,int>
#define vi              vector<int>
#define mii             map<int,int>
#define pqb             priority_queue<int>
#define pqs             priority_queue<int,vi,greater<int> >
#define setbits(x)      __builtin_popcountll(x)
#define zrobits(x)      __builtin_ctzll(x)
#define mod             1000000007
#define inf             1e18
#define ps(x,y)         fixed<<setprecision(y)<<x
#define mk(arr,n,type)  type *arr=new type[n];
#define w(x)            int x; cin>>x; while(x--)
mt19937                 rng(chrono::steady_clock::now().time_since_epoch().count());


void zeus()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}
const int MAX = 5000001;

// structure to store queries
struct Query
{
    int l, r, idx;
};

// cmp function to sort queries according to r
bool cmp(Query x, Query y)
{
    return x.r < y.r;
}

// updating the bit array
void update(int idx, int val, int bit[], int n)
{
    for (; idx <= n; idx += idx & -idx)
        bit[idx] += val;
}

// querying the bit array
int query(int idx, int bit[], int n)
{
    int sum = 0;
    for (; idx > 0; idx -= idx & -idx)
        sum += bit[idx];
    return sum;
}

void answeringQueries(int arr[], int n, Query queries[], int q)
{
    // initialising bit array
    int bit[n + 1];
    memset(bit, 0, sizeof(bit));

    // holds the rightmost index of any number
    // as numbers of a[i] are less than or equal to 10^6
    int last_visit[MAX];
    memset(last_visit, -1, sizeof(last_visit));

    // answer for each query
    int ans[q];
    int query_counter = 0;
    for (int i = 0; i < n; i++)
    {
        // If last visit is not -1 update -1 at the
        // idx equal to last_visit[arr[i]]
        if (last_visit[arr[i]] != -1)
            update (last_visit[arr[i]] + 1, -1, bit, n);

        // Setting last_visit[arr[i]] as i and updating
        // the bit array accordingly
        last_visit[arr[i]] = i;
        update(i + 1, 1, bit, n);

        // If i is equal to r of any query  store answer
        // for that query in ans[]
        while (query_counter < q && queries[query_counter].r == i)
        {
            ans[queries[query_counter].idx] =
                query(queries[query_counter].r + 1, bit, n) -
                query(queries[query_counter].l, bit, n);
            query_counter++;
        }
    }
    //cout << "hello" << endl;
    // print answer for each query
    for (int i = 0; i < q; i++)
        cout << ans[i] << endl;
}
int32_t main() {

    zeus();

    int n, q; cin >> n >> q;

    int a[n];
    forn(i, 0, n) {
        cin >> a[i];
    }

    Query queries[q];

    forn(i, 0, q) {
        int left, right; cin >> left >> right;
        queries[i].l = left - 1;
        queries[i].r = right - 1;
        queries[i].idx = i;
    }
    sort(queries, queries + q, cmp);
    answeringQueries(a, n, queries, q);
    // cout << "hello" << endl;
    return 0;
}

Measured memory_bytes: 66324