//
//  main.cpp
//  cogs182
//
//  Created by Candy on 10/9/16.
//  Copyright © 2016 Candy. All rights reserved.
//

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
using namespace std;
typedef long long ll;
const int N=1e5+5,MOD=1e9+7;
inline int read(){
    char c=getchar();int x=0,f=1;
    while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1;c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘;c=getchar();}
    return x;
}
int n,q,a[N],l,r;
int mx[N][20],mn[N][20];
void initRMQ(){
    for(int i=1;i<=n;i++) mx[i][0]=mn[i][0]=a[i];
    for(int j=1;j<=20;j++)
        for(int i=1;i+(1<<j)-1<=n;i++){
            mx[i][j]=max(mx[i][j-1],mx[i+(1<<(j-1))][j-1]);
            mn[i][j]=min(mn[i][j-1],mn[i+(1<<(j-1))][j-1]);
        }
}
int qmx(int l,int r){
    int k=log(r-l+1)/log(2);
    return max(mx[l][k],mx[r-(1<<k)+1][k]);
}
int qmn(int l,int r){
    int k=log(r-l+1)/log(2);
    return min(mn[l][k],mn[r-(1<<k)+1][k]);
}
int main(int argc, const char * argv[]){
    freopen("lineup.in","r",stdin);
    freopen("lineup.out","w",stdout);
    n=read();q=read();
    for(int i=1;i<=n;i++) a[i]=read();
    initRMQ();
    for(int i=1;i<=q;i++){
        l=read();r=read();
        printf("%d\n",qmx(l,r)-qmn(l,r));
    }
    
    return 0;
}