#include <bits/stdc++.h>

using namespace std;

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

int l[100005];
int f[100005];
int dp[20][100005];
int lg;

int dfs(int x){
    if(l[x] != 0 || x == 1) return l[x];
    l[x] = dfs( f[x] ) + 1;
    return l[x];
}

int ancestor(int x, int lvl){
    while(lvl > 0){
        int p = log2(lvl);
        if( p >= lg ) return 0;
        x = dp[p][x];
        lvl -= pow(2, p);
    }
    return x;
}

int main(){
    cin.tie(0);ios::sync_with_stdio(0);

    int n, q;
    fin >> n >> q;
    f[1] = 0;
    for(int i = 2; i <= n; i++){
        fin >> f[i];
    }       
    for(int i = 1; i <= n; i++) dfs(i);
    lg = log2(n) + 2;
    for(int i = 0; i < lg; i++){
        for(int j = 0; j < n; j++){
            dp[i][j] = 0;
        }
    }
    
    for(int i = 1; i <= n; i++) dp[0][i] = f[i];
    for(int i = 1; i < lg; i++){
        for(int j = 1; j <= n; j++){
            dp[i][j] = dp[i - 1][ dp[i - 1][j] ];
        }
    }

    for(int ii = 0; ii < q; ii++){
        int a, b; fin >> a >> b;
        if(l[a] < l[b]){
            b = ancestor(b, l[b] - l[a]);
        }else if(l[a] > l[b]){
            a = ancestor(a, l[a] - l[b]);
        }

        //cout << "a si b nivelate sunt acuma " << a << " si " << b << endl;

        if(a == b){
            fout << a << endl;
            continue;
        }

        int l = 0, r = lg;
        int last = 0;
        while(l <= r){
            int m = (l + r) / 2;

            if( ancestor(a, m) == ancestor(b, m) ){
                r = m - 1;
                last = ancestor(a, m);
            }else{
                l = m + 1;
            }
        }
        
        fout << last << endl;
    }



    return 0;
}