#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

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

const int N = 100005;
const int E = N * 2;
const int L = 19;

int n, m, nr, t[N], h[N], first[N], euler[E], lg[E], rmq[L][E];
vector <int> a[N];

void DFS(int x, int lev)
{
    nr++;
    h[nr] = lev;
    euler[nr] = x;
    first[x] = nr;
    for(unsigned i=0; i<a[x].size(); i++)
    {
        DFS(a[x][i], lev+1);
        nr++;
        euler[nr] = x;
        h[nr] = lev;
    }
}

void RMQ()
{
    for(int i=2; i<=nr; i++)
        lg[i] = lg[i>>1] + 1;
    for(int i=1; i<=nr; i++)
        rmq[0][i] = i;
    for(int i=1; (1 << i) <= nr; i++)
        for(int j=1; j <= nr - (1 << i); j++)
        {
            const int l = (1 << (i-1));
            rmq[i][j] = rmq[i-1][j];
            if(h[rmq[i][j]] > h[rmq[i-1][j+l]])
                rmq[i][j] = rmq[i-1][j+l];
        }
}

void LCA(int x, int y)
{
    x = first[x], y = first[y];
    if(x > y) swap(x, y);
    const int l = lg[y-x+1];
    int poz = rmq[l][x];
    if(h[poz] > h[rmq[l][y-(1<<l)+1]])
        poz = rmq[l][y-(1<<l)+1];
    fout<<euler[poz]<<'\n';
}

int main()
{
    fin>>n>>m;
    int x, y;
    for(int i=2; i<=n; i++)
    {
        fin>>x;
        a[x].push_back(i);
    }

    DFS(1, 0);
    RMQ();
    while(m--)
    {
        fin>>x>>y;
        LCA(x, y);
    }
    return 0;
}