#include <fstream>

using namespace std;

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

const int nmax = 100001 , log2nmax = 18;
int n , m , nr , niv , lst[nmax] , fiu[nmax] , urm[nmax] , nivel[nmax] , e[2 * nmax] , poz[nmax] , r[log2nmax][2 * nmax] , lg[2 * nmax];

void euler(int x)
{
    int y, p;

    nivel[x] = ++niv;
    e[++nr] = x;
    poz[x] = nr;

    p = lst[x];
    while(p != 0)
    {
        y = fiu[p];

        euler(y);
        e[++nr] = x;

        p = urm[p];
    }

    --niv;
}

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

int main()
{
    int i , j , x , y , L;

    in >> n >> m;
    nr = 0;

    for(i = 2 ; i <= n ; i++)
    {
        in >> x;

        fiu[++nr] = i;
        urm[nr] = lst[x];
        lst[x] = nr;
    }

    nr = 0;
    niv = 0;
    euler(1);

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

    for(i = 1 ; i < log2nmax ; i++)
        for(j = 1 ; j <= nr ; j++)
        {
            if((1 << i) > j)
                continue;

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

    for(i = 2 ; i <= nr ; i++)
        lg[i] = 1 + lg[i / 2];

    for(i = 1 ; i <= m ; i++)
    {
        in >> x >> y;

        x = poz[x];
        y = poz[y];

        if(x > y)
        {
            x = x + y;
            y = x - y;
            x = x - y;
        }

        L = lg[y - x  + 1];

        out << min(r[L][x + (1 << L) - 1] , r[L][y]) << '\n';
    }
    return 0;
}