#include <fstream>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

const int NMAX = 100005;

ifstream cin("lca.in");
ofstream cout("lca.out");

vector <int> g[NMAX];
int nivel[NMAX], first[NMAX];
vector <int> euler;

void dfs(int node, int lvl)
{
    nivel[node] = lvl;
    euler.emplace_back(node);
    first[node] = euler.size() - 1;
    for(auto x: g[node]) {
        dfs(x, lvl + 1);
        euler.emplace_back(node);
    }
}

int dp[NMAX * 2][20];
int main() {
    int n, m;
    cin >> n >> m;
    for(int i = 2; i <= n; ++i) {
        int x;
        cin >> x;
        g[x].emplace_back(i);
    }
    dfs(1, 0);
    for(int i = 0; i < euler.size(); ++i) {
        dp[i][0] = euler[i];
    }
    for(int i = euler.size() - 1; i >= 0 ; --i) {
        for(int j = 1; i + (1 << (j - 1)) - 1 < euler.size(); ++j) {
            dp[i][j] = min(dp[i][j - 1], dp[i + (1 << (j - 1))][j - 1]);
        }
    }
    for(int i = 1; i <= m; ++i) {
        int a, b;
        cin >> a >> b;
        int fa = first[a];
        int fb = first[b];
        if(fa > fb)
            swap(fa, fb);
        int x = fb - fa + 1;
        int lg = (int)log2(x);
        cout << min(dp[fa][lg], dp[fb - (1 << lg) + 1][lg]) << "\n";
    }
    return 0;
}