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

const int MAX_N = 100002;

int N, M, nr;
int E[2 * MAX_N], val[2 * MAX_N], pos[MAX_N], lv[MAX_N], log2[2 * MAX_N], RMQ[MAX_N][20];
vector < int > v[MAX_N];

void DFS(int x, int level) {
    lv[x] = level;
    ++nr;
    E[nr] = x, val[nr] = level, pos[x] = nr;
    for(int i = 0; i < (int) v[x].size(); ++i) {
        DFS(v[x][i], level + 1);
        ++nr;
        E[nr] = x, val[nr] = level;
    }
}

void ComputeRMQ() {
    int n = 2 * N - 1;

    for(int i = 1; i <= n; ++i)
        RMQ[i][0] = i;

    for(int j = 1; (1 << j) <= n; ++j)
        for(int i = 1; i + (1 << j) - 1 <= n; ++i) {
            if(val[RMQ[i][j - 1]] < val[RMQ[i + (1 << (j - 1))][j - 1]])
                RMQ[i][j] = RMQ[i][j - 1];
            else RMQ[i][j] = RMQ[i + (1 << (j - 1))][j - 1];
        }
}

int LCA(int x, int y) {
    x = pos[x], y = pos[y];

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

    int k = log2[y - x + 1];

    if(val[RMQ[x][k]] < val[RMQ[y - (1 << k) + 1][k]])
        return E[RMQ[x][k]];
    else return E[RMQ[y - (1 << k) + 1][k]];
}

int main() {
    ifstream f("lca.in");
    ofstream g("lca.out");

    f >> N >> M;
    for(int i = 2, x; i <= N; ++i) {
        f >> x;

        v[x].push_back(i);
    }

    for(int i = 2; i < 2 * MAX_N; ++i)
        log2[i] = log2[i / 2] + 1;

    DFS(1, 1);
    ComputeRMQ();

    for(int i = 1, x, y; i <= M; ++i) {
        f >> x >> y;
        g << LCA(x, y) << "\n";
    }

    f.close();
    g.close();

    return 0;
}