#include <fstream>
#include <vector>

using namespace std;

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

const int LOGN = 20;
const int NMAX = 100000 + 5;

int N, Q;
int firstAp[NMAX], nivel[NMAX];
vector <int> son[NMAX];

int lg[NMAX];
vector <int> rmq[LOGN];

void DFS(int node)
{
    firstAp[node] = rmq[0].size();
    rmq[0].push_back(node);

    for(int i = 0; i < son[node].size(); i++)
    {
        int it = son[node][i];

        nivel[it] = nivel[node] + 1;
        DFS(it);
        rmq[0].push_back(node);
    }
}

inline int GetMin(int x, int y)
{
    if(nivel[x] < nivel[y])
        return x;

    return y;
}

void RMQ()
{
    for(int i = 1; i <= LOGN - 2; i++)
    {
        if((1 << i) > rmq[0].size())
            break;

        for(int j = 0; j < rmq[0].size(); j++)
        {
            if(j + (1 << i) > rmq[0].size())
                break;

            rmq[i].push_back(GetMin(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]));
        }
    }
}

void InitLg()
{
    for(int i = 2; i <= N; i++)
        lg[i] = 1 + lg[i / 2];
}

int QueryRMQ(int x, int y)
{
    x = firstAp[x];
    y = firstAp[y];

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

    int lenght = (y - x + 1);
    int k = lg[lenght];

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

int main()
{
    int x, y;

    fin >> N >> Q;

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

    DFS(1);
    InitLg();
    RMQ();

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

    return 0;
}