#include <bits/stdc++.h>

using namespace std;

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

const int MAX_LOG = 18;
const int MAX_N = 100005;

int N, Q;
vector<int> arbore[MAX_N];
int parinte[MAX_N], nivel[MAX_N];
int p_curent, p_start[MAX_N], p_end[MAX_N];
int stramos[MAX_LOG][MAX_N];

void dfs(int nod, int nvl = 1)
{
    nivel[nod] = nvl;
    p_start[nod] = ++p_curent;
    for(int fiu : arbore[nod])dfs(fiu, nvl + 1);
    p_end[nod] = ++p_curent;
}

bool este_stramos(int x, int y)
{
    return p_start[x] <= p_start[y] and p_end[y] <= p_end[x];
}

void calculeaza_stramosi()
{
    for(int nod = 1; nod <= N; ++nod)stramos[0][nod] = parinte[nod];
    for(int p = 1; p < MAX_LOG; ++p)for(int nod = 1; nod <= N; ++nod)stramos[p][nod] = stramos[p - 1][stramos[p - 1][nod]];
}

int lca(int x, int y)
{
    if(este_stramos(x, y))return x;
    if(este_stramos(y, x))return y;
    for(int p = MAX_LOG - 1; p >= 0; --p)
    {
        int z = stramos[p][x];
        if(z != 0 and !este_stramos(z, y))x = z;
    }
    return stramos[0][x];
}

int main()
{
    fin >> N >> Q;
    for (int nod = 2; nod <= N; ++nod)
    {
        fin >> parinte[nod];
        arbore[parinte[nod]].push_back(nod);
    }
    p_curent = 0;
    dfs(1);
    calculeaza_stramosi();
    while(--Q)
    {
        int x, y;
        fin >> x >> y;
        fout << lca(x, y) << '\n';
    }
    return 0;
}