#include <fstream>
#include <vector>
#define nmax (int)(1e5+1)
using namespace std;
ifstream cin("lca.in");
ofstream cout("lca.out");
int n,q,x,y,m,poz[nmax],niv[nmax],a[20][3*nmax],e[20][3*nmax],p[3*nmax];
vector<int>v[nmax];
void dfs(int nod){
    e[0][++m]=nod;
    a[0][m]=niv[nod];
    poz[nod]=m;
    for(auto i:v[nod]){
        niv[i]=niv[nod]+1;
        dfs(i);
        e[0][++m]=nod;
        a[0][m]=niv[nod];
    }
}
void rmq(){
    for(int i=1;(1<<i)<=m;i++)
        for(int j=1;j<=m;j++){
            a[i][j]=a[i-1][j];
            e[i][j]=e[i-1][j];
            if(j+(1<<(i-1))<=m&&a[i][j]>a[i-1][j+(1<<(i-1))]){
                a[i][j]=a[i-1][j+(1<<(i-1))];
                e[i][j]=e[i-1][j+(1<<(i-1))];
            }
        }
}
int main()
{
    cin>>n>>q;
    for(int i=2;i<=n;i++){
        cin>>x;
        v[x].push_back(i);
    }
    niv[1]=1;
    dfs(1);
    rmq();
    for(int i=2;i<=m;i++)
        p[i]=p[i/2]+1;
    while(q--){
        cin>>x>>y;
        int st=min(poz[x],poz[y]),dr=max(poz[x],poz[y]),exp=p[dr-st+1],lca=e[exp][st];
        if(a[exp][st]>a[exp][dr-(1<<exp)+1])
            lca=e[exp][dr-(1<<exp)+1];
        cout<<lca<<'\n';
    }
    return 0;
}