#include <bits/stdc++.h>
#define int long long
#define MAX_N 50110
using namespace std;
const int INF_MIN = LLONG_MIN;
const int INF_MAX = LLONG_MAX;

int n, q, maxn[MAX_N * 4], minn[MAX_N * 4];

void build(int k, int l, int r) {
	if (l == r) {
		int v;
		cin >> v;
		maxn[k] = minn[k] = v;
		return;
	}
	int mid = (l + r) >> 1;
	build(2 * k, l, mid);
	build(2 * k + 1, mid + 1, r);
	maxn[k] = max(maxn[k * 2], maxn[k * 2 + 1]);
	minn[k] = min(minn[k * 2], minn[k * 2 + 1]);
}

int qmax(int k, int l, int r, int x, int y) {
	if (l > y || r < x)
		return INF_MIN;
	if (l >= x && r <= y)
		return maxn[k];
	int mid = (l + r) >> 1;
	return max(qmax(k * 2, l, mid, x, y), qmax(k * 2 + 1, mid + 1, r, x, y));
}

int qmin(int k, int l, int r, int x, int y) {
	if (l > y || r < x)
		return INF_MAX;
	if (l >= x && r <= y)
		return minn[k];
	int mid = (l + r) >> 1;
	return min(qmin(k * 2, l, mid, x, y), qmin(k * 2 + 1, mid + 1, r, x, y));
}

signed main() {
	freopen("determine.in", "r", stdin);
	freopen("determine.out", "w", stdout);
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	cin >> n >> q;
	build(1, 1, n);
	
	for (int i = 1; i <= q; i++) {
		int s, t;
		cin >> s >> t;
		if (s > t)
			swap(s, t);
		
		cout << qmax(1, 1, n, s, t) - qmin(1, 1, n, s, t) << '\n';
	}
	
	return 0;
}