#include <bits/stdc++.h>

using namespace std;

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

void usain_bolt()
{
    ios::sync_with_stdio(false);
    fin.tie(0);
}

const int N = 1e5 + 5;

int tour[4 * N], rmq[22][4 * N], lg[4 * N], first[N], height[N];
bool f[N];
vector < int > a[N];

void dfs(int k, int dad = 0)
{
    f[k] = true;
    first[k] = ++tour[0];
    height[k] = height[dad] + 1;
    tour[tour[0]] = k;
    for(auto v : a[k]) {
        if(f[v] == false) {
            dfs(v, k);
            tour[++tour[0]] = k;
        }
    }
}

int main()
{
    usain_bolt();

    int n, m;

    fin >> n >> m;
    for(int i = 1; i < n; ++i) {
        int x;

        fin >> x;
        a[x].push_back(i + 1);
        a[i + 1].push_back(x);
    }
    dfs(1);
    for(int i = 1; i <= tour[0]; ++i) {
        rmq[0][i] = tour[i];
    }
    for(int i = 2; i <= tour[0]; ++i) {
        lg[i] = lg[i >> 1] + 1;
    }
    for(int i = 1; (1 << i) <= tour[0]; ++i) {
        for(int j = 1; j + (1 << i) - 1 <= tour[0]; ++j) {
            if(height[rmq[i - 1][j]] < height[rmq[i - 1][j + (1 << (i - 1))]]) {
                rmq[i][j] = rmq[i - 1][j];
            }
            else {
                rmq[i][j] = rmq[i - 1][j + (1 << (i - 1))];
            }
        }
    }
    for(; m; --m) {
        int x, y, xx, yy;

        fin >> x >> y;
        xx = x, yy = y;
        x = first[x], y = first[y];
        if(x > y) {
            swap(x, y);
        }
        int dif = y - x + 1;
        int base = lg[dif];
        if(height[rmq[base][x]] < height[rmq[base][y - (1 << base) + 1]]) {
            fout << rmq[base][x] << "\n";
        }
        else {
            fout << rmq[base][y - (1 << base) + 1] << "\n";
        }
    }
    return 0;
}