#include <fstream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
using namespace std;
vector<vector<int>>g,lant;
vector<int>poz,e,dp,dep;
vector<int>lg;
void dfs(int nod,int tata)
{
    e.push_back(nod);
    poz[nod]=(int)e.size()-1;
    dp[nod]=1;
    dep[nod]=dep[tata]+1;
    for(auto &c:g[nod])
    {
        if(c==tata)continue;
        dfs(c,nod);
        dp[nod]+=dp[c];
        e.push_back(nod);
    }
}
int rmq[200001][19];
int maxx(int x,int y)
{
    if(dep[x]>dep[y])return y;
    return x;
}
void build_rmq()
{
    int n=(int)e.size()-1;
    lg.resize(n+1);
    lg[0]=lg[1]=0;
    for(int i=2;i<=n;i++)
    {
        lg[i]=lg[i/2]+1;
    }
    for(int i=1;i<=n;i++)
    {
        rmq[i][0]=e[i];
    }
    for(int j=1;(1<<j)<=n;j++)
    {
        for(int i=1;i+(1<<j)-1<=n;i++)
        {
            rmq[i][j]=maxx(rmq[i][j-1],rmq[i+(1<<(j-1))][j-1]);
        }
    }
}
int lca(int x,int y)
{
    int l=min(poz[x],poz[y]);
    int r=max(poz[x],poz[y]);
    int lung=lg[r-l+1];
    return maxx(rmq[l][lung],rmq[r-(1<<lung)+1][lung]);
}
int main()
{
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    int n,q;
    cin>>n>>q;
    g.resize(n+1);
    dep.resize(n+1);
    dp.resize(n+1);
    poz.resize(n+1);
    e.reserve(2*n+1);
    e.push_back(0);
    for(int i=2;i<=n;i++)
    {
        int x;
        cin>>x;
        g[x].push_back(i);
    }
    dfs(1,0);
    build_rmq();
    while(q--)
    {
        int x,y;
        cin>>x>>y;
        cout<<lca(x,y)<<'\n';
    }
}