#include <fstream>
#include <vector>

using namespace std;

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

const int NMAX = 100000;
const int LOGMAX = 18;

int N, M;

vector <int> g[NMAX + 5];

int h[NMAX + 5], log[4 * NMAX];
int firstPos[NMAX + 5];

vector <int> rmq[LOGMAX + 2];

void Dfs(int node, int dad)
{
    h[node] = h[dad] + 1;

    firstPos[node] = rmq[0].size();
    rmq[0].push_back(node);

    for(auto it : g[node])
    {
        Dfs(it, node);
        rmq[0].push_back(node);
    }
}

int GetMin(int a, int b)
{
    if(h[a] < h[b])
        return a;

    return b;
}

void BuildRmq()
{
    log[1] = 0;
    for(int i = 2; i <= 4 * N; i++)
        log[i] = log[i / 2] + 1;

    for(int i = 1; i <= LOGMAX; i++)
        if((1 << i) > rmq[0].size())
            break;
        else
        {
            for(int j = 0; j < rmq[0].size(); j++)
                if(j + (1 << i) > rmq[0].size())
                    break;
                else
                    rmq[i].push_back(GetMin(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]));
        }
}

int QueryRmq(int x, int y)
{
    x = firstPos[x];
    y = firstPos[y];

    if(x > y)
        swap(x, y);

    int l = y - x + 1;
    l = log[l];

    return GetMin(rmq[l][x], rmq[l][y - (1 << l) + 1]);
}

int main()
{
    fin >> N >> M;

    for(int i = 2; i <= N; i++)
    {
        int x;
        fin >> x;
        g[x].push_back(i);
    }

    Dfs(1, 0);
    BuildRmq();

    for(int i = 1; i <= M; i++)
    {
        int x, y;
        fin >> x >> y;
        fout << QueryRmq(x, y) << '\n';
    }

    return 0;
}