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

using namespace std;

const int NMAX = 1e5 + 5;

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

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

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

int dp[2 * NMAX + 5][25];

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) {
            if(nivel[dp[i][j - 1]] < nivel[dp[i + (1 << (j - 1))][j - 1]]) {
                dp[i][j] = dp[i][j - 1];
            } else {
                dp[i][j] = dp[i + (1 << (j - 1))][j - 1];
            }
        }
    }
    for(int i = 1; i <= m; ++i) {
        int x, y;
        cin >> x >> y;
        x = f[x];
        y = f[y];
        if(x > y)
            swap(x, y);
        int lg = log2(y - x + 1);
        cout << min(dp[x][lg], dp[y - (1 << lg) + 1][lg]) << "\n";
    }
    return 0;
}