void RMQ_init(){    for(int i=1; i<=n; i++) dp[i][0]=s[i];    for(int j=1; (1<<j)<=n; j++)        for(int i=1;i+(1<<j)-1<=n;i++)            dp[i][j]=max(dp[i][j-1],dp[i+(1<<(j-1))][j-1]);}int RMQ(int L,int R){    int k=0;    while((1<<(k+1))<=R-L+1) k++;    return max(dp[L][k],dp[R-(1<<k)+1][k]);}

#include <cstring>#include <cmath>#include <cstdio>#include <algorithm>#define N 50010using namespace std;int maxArr[N][16], minArr[N][16];int n, q, num[N];void Sparse_Table(){	int l = (int)(log((double)n) / log(2.0));	for (int j = 1;j <= l;j++)		for (int i = 1; i + (1 << (j - 1) ) - 1 <= n;++i){			maxArr[i][j] = max(maxArr[i][j - 1], maxArr[i + (1 << (j - 1))][j - 1]);			minArr[i][j] = min(minArr[i][j - 1], minArr[i + (1 << (j - 1))][j - 1]);		}}int rmq(int l, int r){	int k = (int)(log((double)(r - l + 1)) / log(2.0));	int Max = max(maxArr[l][k], maxArr[r - (1 << k) + 1][k]);	int Min = min(minArr[l][k], minArr[r - (1 << k) + 1][k]);	return Max - Min;}int main(){	while (~scanf("%d %d", &n, &q)){		memset(maxArr, 0, sizeof(maxArr));		memset(minArr, 0, sizeof(minArr));		for (int i = 1;i <= n;i++){			scanf("%d", &num[i]);			maxArr[i][0] = minArr[i][0] = num[i];		}		Sparse_Table();		int l, r;		while (q--){			scanf("%d%d", &l, &r);			printf("%d\n", rmq(l, r));		}	}	return 0;}