ST表
#include<bits/stdc++.h>
using namespace std;
int f[2000010][24],n;
int get(int x,int y){
int k=log(y-x+1)/log(2);
return max(f[x][k],f[y-(1<<k)+1][k]);
}
int main(){
int i,j,m,t,k;
scanf("%d %d",&n,&m);
for(i=1;i<=n;i++)
scanf("%d",&f[i][0]);
int x=log(n)/log(2)+1;
for(int j=1;j<x;j++)
for(int i=1;i<=n-(1<<j)+1;i++)
f[i][j]=max(f[i][j-1],f[i+(1<<(j-1))][j-1]);
while(m--){
int a,b;
scanf("%d %d",&a,&b);
printf("%d\n",get(a,b));
}
}