#pragma comment(linker,"/STACK:102400000,102400000")

#include <cstdio>

#include <cstring>

#include <string>

#include <cmath>

#include <iostream>

#include <algorithm>

#include <queue>

#include <cstdlib>

#include <stack>

#include <vector>

#include <set>

#include <map>

#define LL long long

#define mod 1000000007

#define inf 0x3f3f3f3f

#define N 50010

#define FILL(a,b) (memset(a,b,sizeof(a)))

#define lson l,m,rt<<1

#define rson m+1,r,rt<<1|1

using namespace std;

int mx[N<<],mn[N<<];

void Pushup(int rt)

{

    mn[rt]=min(mn[rt<<],mn[rt<<|]);

    mx[rt]=max(mx[rt<<],mx[rt<<|]);

}

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

{

    if(l==r)

    {

        int x;

        scanf("%d",&x);

        mn[rt]=mx[rt]=x;

        return;

    }

    int m=(l+r)>>;

    build(lson);

    build(rson);

    Pushup(rt);

}

int querymin(int L,int R,int l,int r,int rt)

{

    if(L<=l&&r<=R)

    {

        return mn[rt];

    }

    int m=(l+r)>>;

    int res=inf;

    if(L<=m)res=min(res,querymin(L,R,lson));

    if(m<R)res=min(res,querymin(L,R,rson));

    return res;

}

int querymax(int L,int R,int l,int r,int rt)

{

    if(L<=l&&r<=R)

    {

        return mx[rt];

    }

    int m=(l+r)>>;

    int res=;

    if(L<=m)res=max(res,querymax(L,R,lson));

    if(m<R)res=max(res,querymax(L,R,rson));

    return res;

}

int main()

{

    int n,m;

    int a,b;

    while(scanf("%d%d",&n,&m)>)

    {

        build(,n,);

        while(m--)

        {

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

            int tallest=querymax(a,b,,n,);

            int shortest=querymin(a,b,,n,);

            printf("%d\n",tallest-shortest);

        }

    }

}