1 #include<cstdio>
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<cmath>
 5 using namespace std;
 6 #define N 200050
 7 int n,m,mi[N][21],mx[N][21];
 8 template<typename T>void read(T &x)
 9 {
10   int k=0; char c=getchar();
11   x=0;
12   while(!isdigit(c)&&c!=EOF)c^=c==‘-‘,c=getchar();
13   if(c==EOF)exit(0);
14   while(isdigit(c))x=x*10+c-‘0‘,c=getchar();
15   x=k?-x:x;
16 }
17 int query_max(int x,int y)
18 {
19   int k=(int)(log(y-x+1)/log(2));
20   return max(mx[x][k],mx[y-(1<<k)+1][k]);
21 }
22 int query_min(int x,int y)
23 {
24   int k=(int)(log(y-x+1)/log(2));
25   return min(mi[x][k],mi[y-(1<<k)+1][k]);
26 }
27 int main()
28 {
29   #ifndef ONLINE_JUDGE
30   freopen("aa.in","r",stdin);
31   #endif
32   read(n);read(m);
33   for(int i=1;i<=n;i++)read(mx[i][0]),mi[i][0]=mx[i][0];
34   for(int i=1;i<=20;i++)
35     for(int j=1;j<=n;j++)
36       if (j+(1<<(i-1))>n)break;
37       else
38     {
39       mx[j][i]=max(mx[j][i-1],mx[j+(1<<(i-1))][i-1]);
40       mi[j][i]=min(mi[j][i-1],mi[j+(1<<(i-1))][i-1]);
41     }
42   for(int i=1;i<=m;i++)
43     {
44       int x,y;
45       read(x);read(y);
46       int ans=query_max(x,y)-query_min(x,y);
47       printf("%d\n",ans);
48     }
49 }