#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

#define Nmax 100005

int n, m, k;
int Rmq[Nmax << 2][20], L[Nmax << 1], H[Nmax << 1], First[Nmax], Log[Nmax << 1];
vector<int> G[Nmax];

void dfs(int nod, int val) {
    L[++k] = val;
    H[k] = nod;
    First[nod] = k;

    for(int y : G[nod]) {
        dfs(y, val + 1);
        L[++k] = val;
        H[k] = nod;
    }
}

void process() {
    Rmq[1][0] = 1;
    for(int i = 2; i <= k; ++i) {
        Log[i] = Log[i >> 1] + 1;
        Rmq[i][0] = i;
    }

    for(int j = 1; (1 << j) <= k; ++j)
        for(int i = 1; i + (1 << j) - 1 <= k; ++i) {
            Rmq[i][j] = Rmq[i][j - 1];
            if(L[Rmq[i + (1 << (j - 1))][j - 1]] < L[Rmq[i][j]])
                Rmq[i][j] = Rmq[i + (1 << (j - 1))][j - 1];
        }
}

int Query(int x, int y) {
    x = First[x];
    y = First[y];
    if(x > y)
        swap(x, y);

    int diff = y - x + 1;
    int lg = Log[diff];

    if(L[Rmq[x][lg]] < L[Rmq[y - (1 << lg) + 1][lg]])
        return H[Rmq[x][lg]];
    return H[Rmq[y - (1 << lg) + 1][lg]];
}

int main()
{
    fin >> n >> m;
    int x, y;
    for(int i = 2; i <= n; ++i) {
        fin >> x;
        G[x].push_back(i);
    }

    dfs(1, 0);
    process();

    for(int i = 1; i <= m; ++i) {
        fin >> x >> y;
        fout << Query(x, y) << '\n';
    }
    return 0;
}