#include <bits/stdc++.h>
#define zeros(x) x & (-x)

using namespace std;

const int MAXN = 1e5 + 65;
const int INF = 1e8;

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

vector <int > g[MAXN];
int euler[2 * MAXN], lvl[MAXN], first[MAXN];
int rmq[30][2 * MAXN], p;

///rmq[power(dif)][first[x]] = min(lvl[eulerp[

void dfs(int node, int papa){

    euler[++p] = node;
    first[node] = p ;
    lvl[node] = lvl[papa] + 1;

    for(auto x : g[node]){
        if(x != papa){
            dfs(x, node);
            euler[++p] = node;
        }
    }
}

int main(){

    int n , m ; fin >> n >> m;
    for(int i = 2; i <= n; ++i){
        int x; fin >> x;

        g[x].push_back(i);
    }
    dfs(1, 0);
    /// rmq - nodul cu lvl minim in euler

    for(int i = 1; i <= p; ++i){
        rmq[0][i] = euler[i];
    }

    for(int i = 1; i <= 30; ++i){
        for(int j = 1; j <= p; ++j){
            if(j + (1 << ( i - 1 )) <= p){
                if(lvl[rmq[i - 1][j]] < lvl[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(int i = 1; i <= m; ++i){
        int x, y; fin >> x >> y;
        x = first[x];
        y = first[y];

        if(y < x) swap(x, y);
        int dif = y - x + 1, power = 0;

        for(int j = 30; j >= 0 ; --j){
            if((1 << j) & dif){
                power = j;
                break;
            }
        }

        int ans = 0;

        if(lvl[rmq[power][x]] <= lvl[rmq[power][y - (1 << power) + 1]])
            ans = rmq[power][x];
        else ans = rmq[power][y - (1 << power) + 1];

        fout << ans << '\n';
    }
    return 0;
}