#include <map>
#include <set>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
#include <iostream>
#include <stack>
#include <cmath>
#include <string>
#include <vector>
#include <cstdlib>
//#include <bits/stdc++.h>
//#define LOACL
#define space " "
using namespace std;
typedef long long LL;
typedef __int64 Int;
typedef pair<int, int> paii;
const int INF = 0x3f3f3f3f;
const double ESP = 1e-5;
const double PI = acos(-1.0);
const int MOD = 1e9 + 7;
const int MAXN = 200000 + 10;
int data[MAXN];
struct node {int l, r, value;
} segmin[MAXN], segmax[MAXN];
int build_segm_max(int x, int lson, int rson) {segmax[x].l = lson;segmax[x].r = rson;if (lson != rson) {int a = build_segm_max(x << 1, lson, (rson + lson)/2);int b = build_segm_max((x << 1) + 1, (rson + lson)/2 + 1, rson);return segmax[x].value = max(a, b);}return segmax[x].value = data[lson];
}
int build_segm_min(int x, int lson, int rson) {segmin[x].l = lson;segmin[x].r = rson;if (lson != rson) {int a = build_segm_min(x << 1, lson, (rson + lson)/2);int b = build_segm_min((x << 1) + 1, (rson + lson)/2 + 1, rson);return segmin[x].value = min(a, b);}return segmin[x].value = data[lson];
}
int query_seg_max(int x, int lson, int rson) {if (segmax[x].l > rson || segmax[x].r < lson) return 0;if (segmax[x].l >= lson && segmax[x].r <= rson) return segmax[x].value;int a = query_seg_max(x << 1, lson, rson);int b = query_seg_max((x << 1) + 1, lson, rson);return max(a, b);
}
int query_seg_min(int x, int lson, int rson) {if (segmin[x].l > rson || segmin[x].r < lson) return INF;if (segmin[x].l >= lson && segmin[x].r <= rson) return segmin[x].value;int a = query_seg_min(x << 1, lson, rson);int b = query_seg_min((x << 1) + 1, lson, rson);return min(a, b);
}
int main() {int N, Q, a, b;scanf("%d%d", &N, &Q);for (int i = 1; i <= N; i++) scanf("%d", &data[i]);build_segm_max(1, 1, N); build_segm_min(1, 1, N);for (int i = 0; i < Q; i++) {scanf("%d%d", &a, &b);printf("%d\n", query_seg_max(1, a, b) - query_seg_min(1, a, b));}return 0;
}