#include <bits/stdc++.h>
using namespace std;

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

const int N_MAX = 1e5, LG_N = 19;

int n, m;
vector<int> gr[N_MAX + 2];

int rmq[LG_N + 2][4 * N_MAX + 2];

int len;
int eul[4 * N_MAX + 2], first[N_MAX + 2], depth[N_MAX + 2];
void dfs(int node, int daddy)
{
    eul[++len] = node;
    depth[len] = depth[daddy] + 1;
    first[node] = len;


    for(auto it: gr[node])
        if(it != daddy)
        {
            dfs(it, node);

            eul[++len] = node;
            depth[len] = depth[daddy] + 1;
        }
}

int lca(int x, int y)
{
    int left = first[x], right = first[y];
    if(left > right)
        swap(left, right);

    int lg = log2(right - left + 1);
    if(depth[rmq[lg][left]] < depth[rmq[lg][right - (1 << lg) + 1]])
        return eul[rmq[lg][left]];
    else
        return eul[rmq[lg][right - (1 << lg) + 1]];
}

int main()
{
    in >> n >> m;

    int x, y;
    for(int i = 1; i < n; i++)
    {
        in >> x;
        gr[i + 1].push_back(x);
        gr[x].push_back(i + 1);
    }

    dfs(1, 0);

    for(int j = 1; j <= len; j++)
        rmq[0][j] = j;

    for(int i = 1; (1 << i) <= len; i++)
        for(int j = 1; j <= len - (1 << i) + 1; j++)
        {
            rmq[i][j] = rmq[i - 1][j];
            if(depth[rmq[i][j]] > depth[rmq[i - 1][j + (1 << (i - 1))]])
               rmq[i][j] = rmq[i - 1][j + (1 << (i - 1))];
        }

    while(m--)
    {
        in >> x >> y;

        out << lca(x, y) << '\n';
    }

    return 0;
}