#include <bits/stdc++.h>
using namespace std;
#define N 500010
int n,m,a,poz[N],l,k,pozy,pozx,lg[N],rmq[21][N],level[N];
bool viz[N];
vector<int>v[N],eu;

void euler(int x, int lev)
{
    if(!viz[x])
    {
        viz[x] = 1;
        poz[x] = eu.size()+1;
    }
    level[x] = lev;
    eu.push_back(x);
    for(int i=0;i<v[x].size();i++)
    {
        euler(v[x][i], lev+1);
        eu.push_back(x);
    }
}

int meen(int x,int y)
{
    if(level[x]<level[y]) return x;
    return y;
}


int main()
{
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    cin>>n>>m;
    lg[1] = 0;
    for(int i=2;i<=n;i++)
    {
        cin>>a;
        v[a].push_back(i);
    }
    euler(1, 0);
    int eus = eu.size();
    for(int i=0;i<eus;i++)
    {
        rmq[0][i] = eu[i];
        if(i>=2) lg[i] = lg[i/2]+1;
    }

    for(k=1;(1<<k)<=eus;k++)
        for(int j = 0;j + (1<<k)-1<eus;j++)
            rmq[k][j] = meen(rmq[k-1][j], rmq[k-1][j+(1<<(k-1))]);

    int x,y;
    while(m--)
    {
        cin>>x>>y;
        pozx = min(poz[x],poz[y]);
        pozy = max(poz[y],poz[x]);
        pozx--; pozy--;
        k = lg[pozy-pozx+1];
        cout<<meen(rmq[k][pozx], rmq[k][pozy - (1<<(k))+1])<<'\n';

    }

    return 0;
}