#include <fstream>
#include <vector>

using namespace std;

const int NMAX = 2e5 + 1, SQRT = 21;

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

int n, m, niv[NMAX], ind[NMAX],
    lg[NMAX], t[SQRT][NMAX];
vector<int> G[NMAX], E;

void citire()
{
    fin >> n >> m;
    for(int i = 2, x; i <= n; ++i)
    {
        fin >> x;
        G[x].push_back(i);
    }
}

void dfs(int x)
{
    E.push_back(x);
    ind[x] = E.size();
    for(const auto& y : G[x])
    {
        niv[y] = niv[x] + 1;
        dfs(y);
        E.push_back(x);
    }
}

void genRmq()
{
    int k = E.size();
    lg[0] = -1;
    for(int i = 1; i <= k; ++i)
    {
        lg[i] = lg[i >> 1] + 1;
        t[0][i] = E[i - 1];
    }
    lg[0] = 0;
    for(int i = 1; (1 << i) <= k; ++i)
        for(int j = 1; j + (1 << i) - 1 <= k; ++j)
        {
            t[i][j] = t[i - 1][j];
            int j2 = j + (1 << (i - 1));
            if(niv[t[i][j]] > niv[t[i - 1][j2]]) t[i][j] = t[i - 1][j2];
        }
}

int lca(int x, int y)
{
    x = ind[x], y = ind[y];
    if(x > y) swap(x, y);
    int k = lg[y - x + 1],
        sol = t[k][x],
        j = y - (1 << k) + 1;
    if(niv[sol] > niv[t[k][j]]) sol = t[k][j];
    return sol;
}

int main()
{
    int x, y;
    citire();
    dfs(1);
    genRmq();
    while(m--)
    {
        fin >> x >> y;
        fout << lca(x, y) << '\n';
    }
    return 0;
}