#include <bits/stdc++.h>

#pragma optimize GCC ("Ofast")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

///#include <tryhardmode>
///#include <GODMODE::ON>

using namespace std;

#define cin fin
#define cout fout

ifstream fin ("lca.in");
ofstream fout ("lca.out");

const int NMAX=1e5+5;

vector<int>v[NMAX];
int rmq[25][2*NMAX];
int lg[2*NMAX];
int lvl[2*NMAX];
int ti[NMAX];
int kon;

void dfs(int p,int tata)
{
    lvl[p]=lvl[tata]+1;
    ti[p]=++kon;
    rmq[0][kon]=p;
    for(auto i:v[p])
    {
        if(i!=tata)
        {
            dfs(i,p);
            rmq[0][++kon]=p;
        }
    }
}

bool cmp(int x,int y)
{
    return lvl[x]<lvl[y];
}

int query(int x,int y)
{
    int interv=y-x+1;
    int l=lg[interv];
    return min(rmq[l][x],rmq[l][x+interv-(1<<l)],cmp);
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    int n,q,i,j,e;
    cin>>n>>q;
    for(i=2;i<=n;i++)
    {
        int x;
        cin>>x;
        v[i].push_back(x);
        v[x].push_back(i);
    }
    dfs(1,0);
    lg[1]=0;
    for(i=2;i<=kon;i++)
        lg[i]=lg[i/2]+1;
    for(e=1;(1<<e)<=kon;e++)
    {
        for(i=1;i<=kon;i++)
        {
            if(i+(1<<(e-1))>kon)
                continue;
            rmq[e][i]=min(rmq[e-1][i],rmq[e-1][i+(1<<(e-1))],cmp);
        }
    }
    while(q--)
    {
        int x,y;
        cin>>x>>y;
        x=ti[x];
        y=ti[y];
        if(x>y)
            swap(x,y);
        cout<<query(x,y)<<"\n";
    }
    return 0;
}