#include <fstream>
#include <vector>
using namespace std;

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


const int N = 100001;
const int LOGN = 18;

int n, m, ne, niv;
int e[2 * N], nivel[2 * N], poz[N];
int r[LOGN][2 * N], lg[2 * N];
vector<int> a[N];


void euler(int x)
{
    e[++ne] = x;
    poz[x] = ne;
    nivel[x] = ++niv;

    for(size_t i = 0; i < a[x].size(); i++)
    {
        int y = a[x][i];

        euler(y);
        e[++ne] = x;
    }
    niv--;
}


inline int min(int x, int y)
{
    return (nivel[x] < nivel[y]) ? x : y;
}

void rmq()
{
    lg[1] = 0;
    for(int i = 2; i <= ne; i++)
        lg[i] = lg[i / 2] + 1;

    for(int i = 1; i <= ne; i++)
        r[0][i] = e[i];

    for(int i = 1; i <= lg[ne]; i++)
        for(int j = 1; j <= ne; j++)
        {
            if(j + (1 << i) - 1 > ne)
                continue;

            r[i][j] = min(r[i - 1][j], r[i - 1][j + (1 << (i - 1))]);
        }
}

void query(int x, int y)
{
    x = poz[x];
    y = poz[y];

    if(x > y)
    {
        int aux = x;
        x = y;
        y = aux;
    }

    int l = lg[y - x + 1];
    out << min(r[l][x], r[l][y - (1 << l) + 1]) << '\n';
}


void citire()
{
    in >> n >> m;

    for(int i = 2; i <= n; i++)
    {
        int x;
        in >> x;
        a[x].push_back(i);
    }
}

int main()
{
    citire();
    ne = 0;
    niv = -1;
    euler(1);
    rmq();
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        in >> x >> y;
        query(x, y);
    }
    return 0;
}