#include <bits/stdc++.h>

using namespace std;

const int Maxn = 1e5 + 1e4;

ifstream f("lca.in");
ofstream g("lca.out");

int tata[Maxn];
int dp[Maxn][25];
int nivel[Maxn];
vector <int> gr[Maxn];

void dfs(int node, int boss, int lvl){
    nivel[node] = lvl;
    for(int i = 0; i < gr[node].size(); ++ i){
        int x = gr[node][i];
        if(x == boss) continue;
        dfs(x, node, lvl+1);
    }
}

int stramos(int x, int y){
    for(int lg = 20; lg >= 0; --lg){
        if((1<<lg) <= y){
            x = dp[x][lg];
            y -= (1<<lg);
        }
    }
    return x;
}

int solve(int x, int y){
    if(nivel[x] < nivel[y]) swap(x, y);
    int dif = nivel[x]-nivel[y];
    x = stramos(x, dif);
    int niv = nivel[x]-1;
    for(int lg = 20; lg >= 0; -- lg){
        if(stramos(x, niv-(1<<lg)) == stramos(y, niv-(1<<lg))){
            niv -= 1<<lg;
        }
    }

    return stramos(x, niv);

}

int main(){
    int n, m;
    f >> n >> m;
    dp[1][0] = 0;
    tata[1] = 0;
    for(int i = 2; i <= n; ++ i){
        f >> dp[i][0];
        tata[i] = dp[i][0];
        gr[i].push_back(tata[i]);
        gr[tata[i]].push_back(i);
    }
    dfs(1, 0, 1);

    for(int j = 1; j <= 20; ++ j){
        for(int i = 1; i <= n; ++ i){
            dp[i][j] = dp[dp[i][j-1]][j-1];
        }
    }
    for(int i = 1; i <= m; ++ i){
        int x, y;
        f >> x >> y;
        g << solve(x, y) << '\n';
    }
    return 0;
}