#include <iostream>

#include <algorithm>

#include <cmath>

#include <cstdio>

#include <cstdlib>

using namespace std;

const int MAXN=1e5+;

const int INF=0x7fffffff;

typedef long long ll;

int lazy[MAXN<<],max_[MAXN<<],min_[MAXN<<];

//这里在push_up的时候我们将区间最大值和区间最小值都更新一下

void push_up(int node)

{

    max_[node]=max(max_[node<<],max_[node<<|]);

    min_[node]=min(min_[node<<],min_[node<<|]);

}

void build(int node,int l,int r)

{

    if(l==r)

    {

        scanf("%d",&max_[node]);

        min_[node]=max_[node];

        return ;

    }

    int mid=(l+r)>>;

    build(node<<,l,mid);

    build(node<<|,mid+,r);

    push_up(node);

}

int query1(int node,int l,int r,int x,int y)

{

    if(x<=l&&y>=r)

    {

        return max_[node];

    }

    int max1=,min1=INF;

    int mid=(l+r)>>;

    if(x<=mid)max1=max(max1,query1(node<<,l,mid,x,y));

    if(y>mid)max1=max(query1(node<<|,mid+,r,x,y),max1);

    return max1;

}

int query2(int node,int l,int r,int x,int y)

{

    if(x<=l&&y>=r)

    {

        return min_[node];

    }

    int min1=INF;

    int mid=(l+r)>>;

    if(x<=mid)min1=min(min1,query2(node<<,l,mid,x,y));

    if(y>mid)min1=min(query2(node<<|,mid+,r,x,y),min1);

    return min1;

}

int main()

{

    int n,k;

    scanf("%d%d",&n,&k);

    build(,,n);

    for(int i=;i<=k;i++)

    {

        int a,b;

        scanf("%d%d",&a,&b);

        printf("%d\n",query1(,,n,a,b)-query2(,,n,a,b));

    }

    return ;

}