#include<bits/stdc++.h>
using namespace std;
#define ll long long int
const int MAXN = 200005;
const int SQRTN = 100;
bool ar[200007];
vector<ll>p;
void seive()
{
for(int i=0;i<=MAXN;i++)
ar[i]=true;
ar[0]=ar[1]=false;
for(int i=2;i*i<=MAXN;i++)
{
if(ar[i]==true)
{
for(int j=i*i;j<=MAXN;j+=i)
{
ar[j]=false;
}
}
}
for(int i=1;i<=MAXN;i++)
{
if(ar[i]==true)
p.push_back(i);
}
}
//Mo's Algorithm
struct Query {
int l, r, idx;
};
vector<int> ans;
vector<int> arr;
vector<Query> queries;
int frequency[MAXN];
unordered_map<int, int> countMap;
int threshold;
bool compare(const Query &a, const Query &b) {
int block_a = a.l / SQRTN;
int block_b = b.l / SQRTN;
if (block_a != block_b)
return block_a < block_b;
return (block_a % 2 == 0) ? (a.r < b.r) : (a.r > b.r);
}
void add(int position, int threshold) {
int element = arr[position];
countMap[element]++;
if (countMap[element] > threshold) {
frequency[element]++;
}
}
void remove(int position, int threshold) {
int element = arr[position];
if (countMap[element] > threshold) {
frequency[element]--;
}
countMap[element]--;
}
int get_min_valid_candidate(int threshold) {
int min_candidate = -1;
for (const auto &entry : countMap) {
int element = entry.first;
if (entry.second > threshold && (min_candidate == -1 || element < min_candidate)) {
min_candidate = element;
}
}
return min_candidate;
}
void process_queries(int n, int q) {
int L = 0, R = -1;
for (Query &query : queries) {
int l = query.l - 1, r = query.r - 1;
threshold = (r - l + 1) / 3;
while (R < r) add(++R, threshold);
while (R > r) remove(R--, threshold);
while (L < l) remove(L++, threshold);
while (L > l) add(--L, threshold);
ans[query.idx] = get_min_valid_candidate(threshold);
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int n, q;
cin >> n >> q;
arr.resize(n);
for (int i = 0; i < n; i++) {
cin >> arr[i];
}
queries.resize(q);
ans.resize(q, -1);
for (int i = 0; i < q; i++) {
int l, r;
cin >> l >> r;
queries[i] = {l, r, i};
}
sort(queries.begin(), queries.end(), compare);
process_queries(n, q);
for (int i = 0; i < q; i++) {
cout << ans[i] << "\n";
}
return 0;
}