#include<bits/stdc++.h>

using namespace std;

const int N = 2e5 + 5;
const int M = 1e6 + 5;

int n, m, a[N], ans[N];
bool flag[M];
vector<int> fac[M];
deque<int> d[M];
priority_queue<int, vector<int> > v;

int pos[N];
struct Node {
	int l, r, k;
	bool operator<(Node B) {
		if (pos[l] != pos[B.l]) {
			return pos[l] < pos[B.l];
		}
		if (pos[l] & 1) {
			return r > B.r;
		}
		return r < B.r;
	}	
}q[N];
void add(int x) {
	for (auto y : fac[a[x]]) {
		if (d[y].empty() || x > d[y].back()) {
			d[y].push_back(x);
		} else {
			d[y].push_front(x);
		}
		if (flag[y] || d[y].size() < 3) {
			continue;
		}
		if (d[y][1] - d[y].front() <= d[y].back() - d[y][1]) {
			flag[y] = 1;
			v.push(y);
		}
	}
}
void del(int x) {
	for (auto y : fac[a[x]]) {
		if (d[y].back() == x) {
			d[y].pop_back();
		} else {
			d[y].pop_front();
		}
	}
}

void solve() {
	cin>>n>>m;
	int block = sqrt(n);
	for (int i = 1; i <= n; i++) {
		cin>>a[i];
		pos[i] = (i - 1) / block + 1;
		if (fac[a[i]].empty()) {
			int top = sqrt(a[i]);
			for (int j = 1; j <= top; j++) {
				if (a[i] % j == 0) {
					fac[a[i]].push_back(j);
					if (j != a[i] / j) {
						fac[a[i]].push_back(a[i] / j);
					}
				}
			}
		}
	}

	for (int i = 1; i <= m; i++) {
		cin>>q[i].l>>q[i].r;
		q[i].k = i;
	}
	sort(q + 1, q + m + 1);

	int l = q[1].l, r = q[1].r;
	for (int i = l; i <= r; i++) {
		add(i);
	}
	for (int i = 1; i <= m; i++) {
		while (l > q[i].l) add(--l);
		while (r < q[i].r) add(++r);
		while (l < q[i].l) del(l++);
		while (r > q[i].r) del(r--);

		while (!v.empty()) {
			int t = v.top();
			if (d[t].size() < 3 || d[t][1] - d[t].front() > d[t].back() - d[t][1]) {
				flag[t] = 0;
				v.pop();
			} else {
				break;
			}
		}

		if (v.empty()) {
			ans[q[i].k] = 0;
		} else {
			ans[q[i].k] = v.top();
		}
	}

	for (int i = 1; i <= m; i++) {
		cout<<ans[i]<<'\n';
	}
}

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);

	int T = 1;
	// cin>>T;
	while (T--) {
		solve();
	}
}