#include<bits/stdc++.h>
	using namespace std;
	typedef long long ll;
	const int N = 17;
	int a[100010][N];

	int main() {
		int n, m,t=1,l,r;
		cin >> n >> m;
		while (t<=n) {
			cin >> a[t][0];
			t++;
		}
		for (int j = 1; j < N; j++)
		{
			int d = n - (1 << j) + 1;
			for (int i = 1; i <= d; i++)
			{
				a[i][j] = max(a[i][j-1], a[i+(1<<(j-1))][j - 1]);
			}
		}
	
		while (m--) {
			cin >> l >> r;
			int d = log((r - l + 1)) / log(2);
			int ans = max(a[l][d],a[r-(1<<d)+1][d]);
			cout << ans << "\n";
		}
		return 0;
	}

P3865,TLE了,如何优化大佬们!