#include<iostream>
using namespace std;
struct tree
{
	int l,r,Max,Min;
	#define l(x) t[x].l
	#define r(x) t[x].r
	#define Max(x) t[x].Max
	#define Min(x) t[x].Min
}t[800005];
int n,m,a[180005];
void build(int p,int l,int r)
{
	l(p)=l,r(p)=r;
	if(l==r)
	{
		Max(p)=a[l];
		Min(p)=a[l];
		return;
	}
	int mid=(l+r)>>1;
	build(p*2,l,mid);
	build(p*2+1,mid+1,r);
	Max(p)=max(Max(p*2),Max(p*2+1));
	Min(p)=min(Min(p*2),Min(p*2+1));
}
int ask_Max(int p,int l,int r)
{
	if(l<=l(p)&&r>=r(p))
	{
		return Max(p);
	}
	int mid=(l(p)+r(p))>>1;
	int ans=-1;
	if(l<=mid)ans=max(ans,ask_Max(p*2,l,r));
	if(r>mid)ans=max(ans,ask_Max(p*2+1,l,r));
	return ans;
}
int ask_Min(int p,int l,int r)
{
	if(l<=l(p)&&r>=r(p))
	{
		return Min(p);
	}
	int mid=(l(p)+r(p))>>1;
	int ans=0x3f;
	if(l<=mid)ans=min(ans,ask_Min(p*2,l,r));
	if(r>mid)ans=min(ans,ask_Min(p*2+1,l,r));
	return ans;
}
int main()
{
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
	}
	build(1,1,n);
	while(m--)
	{
		int l,r;
		scanf("%d%d",&l,&r);
		printf("%d\n",ask_Max(1,l,r)-ask_Min(1,l,r));
	}
	return 0;
}