#include <fstream>
#include <vector>
#include <cmath>
using namespace std;
ifstream fi("lca.in");
ofstream fo("lca.out");

const int MAX_N = 100002;

int N, M, nr;
int E[2 * MAX_N], niv[2 * MAX_N], nod[MAX_N], r[2 * MAX_N][20];
vector < int > G[MAX_N];

void DFS(int x, int nv)
{
    ++nr;
    E[nr] = x, niv[nr] = nv, nod[x] = nr;
    for(auto y : G[x])
    {
        DFS(y, nv + 1);
        ++nr;
        E[nr] = x, niv[nr] = nv;
    }
}

void RMQ()
{
    int n = 2 * N - 1;
    for(int i = 1; i <= n; ++i)  r[i][0] = i;

    for(int j = 1; (1 << j) <= n; ++j)
        for(int i = 1; i + (1 << j) - 1 <= n; ++i)
          if (niv[r[i][j - 1]] < niv[r[i + (1 << (j - 1))][j - 1]])
                  r[i][j] = r[i][j - 1];
             else r[i][j] = r[i + (1 << (j - 1))][j - 1];

}

int LCA(int x, int y)
{
    if(x > y) swap(x, y);
    int k = log2(y - x  + 1);

    if(niv[r[x][k]] < niv[r[y - (1 << k) + 1][k]])
        return E[r[x][k]];
    return E[r[y - (1 << k) + 1][k]];
}

int main()
 {

    fi >> N >> M;
    for(int i = 2, x; i <= N; ++i)
    {
        fi >> x;
        G[x].push_back(i);
    }

    DFS(1, 1);
    RMQ();

    for(int i = 1, x, y; i <= M; ++i)
        {
        fi >> x >> y;
        fo << LCA(nod[x],nod[y]) << "\n";
        }


    return 0;
}