#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp> 
#define ll          long long
#define pb          push_back
#define INF         9223372036854775807
#define    endl        '\n'
#define pii         pair<ll int,ll int>
#define vi          vector<ll int>
#define all(a)      (a).begin(),(a).end()
#define F           first
#define S           second
#define sz(x)       (ll int)x.size()
#define hell        1000000007
#define rep(i,a,b)    for(ll int i=a;i<b;i++)
#define lbnd        lower_bound
#define ubnd        upper_bound
#define bs          binary_search
#define mp          make_pair
#define lower(u)    transform(u.begin(), u.end(), u.begin(), ::tolower);//convert string u to lowercase;
#define upper(u)    transform(u.begin(), u.end(), u.begin(), ::toupper);
using namespace std;

using namespace __gnu_pbds; 
  
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> 
#define N  100005
const int MAX = 500005; 
  
// 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++; 
        } 
    } 
  
    // print answer for each query 
    for (int i=0; i<q; i++) 
        cout << ans[i] << endl; 
} 
void solve()
{
    ll n,q;
    cin>>n>>q;
    int a[n];
    rep(i,0,n)cin>>a[i];
    Query queries[q];
    rep(i,0,q)
    {
        ll l,r;
        cin>>l>>r;
        l--;
        r--;
        queries[i].l=l;
        queries[i].r=r;
        queries[i].idx=i;

    }
    sort(queries, queries+q, cmp); 
    answeringQueries(a, n, queries, q);

}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    int TESTS=1;
//    cin>>TESTS;
    while(TESTS--)
    {
        solve();
    }
    return 0;
}

Measured memory_bytes: 17444