#include<bits/stdc++.h>//1AC 2WA 7TIE
using namespace std;
int n,q,a[1000005],x,y;
int main(){
	scanf("%d%d",&n,&q);
	for(int i=1;i<=n;i++)scanf("%d",&a[i]);
	for(int i=1;i<=q;i++){
	   cin>>x>>y; 
	   if(x==y)cout<<0;
	   else{
	       sort(a+1+x,a+1+y);
	       cout<<a[y]-a[x];
       }
	   cout<<endl;
    }
	return 0;
}