#include <iostream>
#include <fstream>
#include <vector>
#include <math.h>

using namespace std;

vector<int> p, level, v;
int sq;

int lca(int x, int y) {
    if (level[x] > level[y])
        while (level[x] > level[y]) x = p[x];
    else if (level[y] > level[x])
        while (level[y] > level[x]) y = p[y];
    while (x!=y) {
        x = p[x];
        y = p[y];
    }

    return x;

}

int mainLca(int x, int y) {
    if(level[x]/sq > level[y]/sq)
        while (level[x] / sq > level[y] / sq){
            x = v[x];
        }
    else if (level[y] / sq > level[x] / sq)
        while (level[y] / sq > level[x] / sq) {
            y = v[y];
        }
    if (x == y) return x;
    while (v[x] != v[y]) {
        x = v[x];
        y = v[y];
    }
    return lca(x, y);
}

int findNext(int root,int z) {
    if (v[root] != -1) return v[root];
    int l = level[root];
    int zone = l / sq;
    if (zone == z - 1)
        return root;
    v[root] = findNext(p[root], z);
    return v[root];
}

int findLevel(int root) {
    if (level[root] != -1) return level[root];
    level[root] = findLevel(p[root]) + 1;
    return level[root];
}

int main() {

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

    int n, m;
    fin >> n >> m;
    p.resize(n + 1, -1);
    level.resize(n + 1, -1);
    v.resize(n + 1, -1);
    for (int i = 2;i <= n;++i) {
        int x;
        fin >> x;
        p[i] = x;
    }
    level[1] = 1;
    sq = 0;
    for (int i = 2;i <= n;++i) {
        findLevel(i);
        if (level[i] > sq) sq = level[i];
    }
    v[1] = 0;
    for (int i = 2;i <= n;++i)
        findNext(i, level[i] / sq);

    sq = sqrt(sq);

    while (m--) {
        int x, y;
        fin >> x >> y;
        fout << mainLca(x, y) << '\n';
    }

    return 0;
}