#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#define fo(i,a,b) for(i=a;i<=b;i++)
#define fod(i,a,b) for(i=a;i>=b;i--)
#define rep(i,a) for(i=first[a];i;i=next[i])
using namespace std;
const int maxn=100007;
int i,j,k,n,m,ans[maxn],l,r;
int a[maxn],dfn,tongl,tongr;
int num;
int t[maxn*30];
struct node{
int l,r,c;
}duan[maxn*30],wen[maxn];
void build(int x,int l,int r){
if(l==r){
duan[++num].l=l,duan[num].r=r;
return;
}
int mid=a[++dfn];
build(x*2,l,mid);
build(x*2+1,mid+1,r);
duan[++num].l=l,duan[num].r=r;
}
bool cmp(node x,node y){
return x.l<y.l||x.l==y.l&&x.r<y.r;
}
int lowbit(int x){
return x&(-x);
}
void add(int x,int y){
for(;x<=n;x+=lowbit(x))t[x]+=y;
}
int find(int x){
int o=0;
for(;x;x-=lowbit(x))o+=t[x];
return o;
}
int main(){
scanf("%d%d",&n,&m);
fo(i,1,n-1){
scanf("%d",&a[i]);
}
build(1,1,n);
fo(i,1,m)scanf("%d%d",&wen[i].l,&wen[i].r),wen[i].c=i;
sort(wen+1,wen+1+m,cmp);
sort(duan+1,duan+1+num,cmp);
k=1;
fo(i,1,num)add(duan[i].r,1);
fo(i,1,m){
while(duan[k].l<wen[i].l)add(duan[k].r,-1),k++;
ans[wen[i].c]=2*(wen[i].r-wen[i].l+1)-find(wen[i].r);
}
fo(i,1,m)printf("%d\n",ans[i]);
}