#include <fstream>
#include <iostream>
#include <vector>
#include <bitset>
#include <string.h>
#include <algorithm>
#include <iomanip>
#include <math.h>
#include <time.h>
#include <stdlib.h>
#include <set>
#include <map>
#include <string>
#include <queue>
#include <deque>

using namespace std;

const char infile[] = "lca.in";
const char outfile[] = "lca.out";

ifstream fin(infile);
ofstream fout(outfile);

const int MAXN = 100005;
const int oo = 0x3f3f3f3f;

typedef vector<int> Graph[MAXN];
typedef vector<int> :: iterator It;

const inline int min(const int &a, const int &b) { if( a > b ) return b;   return a; }
const inline int max(const int &a, const int &b) { if( a < b ) return b;   return a; }
const inline void Get_min(int &a, const int b)    { if( a > b ) a = b; }
const inline void Get_max(int &a, const int b)    { if( a < b ) a = b; }

Graph g;
int n, m, k, euler[MAXN << 1], first[MAXN], level[MAXN << 1], rmq[20][MAXN << 1], Log[MAXN << 1];

inline void dfs(int node, int actlevel) {
    first[node] = ++ k;
    euler[k] = node;
    level[k] = actlevel;
    for(It it = g[node].begin(), fin = g[node].end(); it != fin ; ++ it) {
        dfs(*it, actlevel + 1);
        euler[++k] = node;
        level[k] = actlevel;
    }
}

inline void buildrmq() {
    for(int i = 2 ; i <= k ; ++ i)
        Log[i] = Log[i >> 1] + 1;
    for(int i = 1 ; i <= k ; ++ i)
        rmq[0][i] = i;
    for(int i = 1 ; (1 << i) <= k ; ++ i) {
        int aux = (1 << (i - 1));
        for(int j = 1 ; j + (1 << i) - 1 <= k ; ++ j) {
            rmq[i][j] = rmq[i - 1][j];
            if(level[rmq[i][j]] > level[rmq[i - 1][j + aux]])
                rmq[i][j] = rmq[i - 1][j + aux];
        }
    }
}

inline int query(int x, int y) {
    x = first[x];
    y = first[y];
    if(x > y)
        swap(x, y);
    int lg = Log[y - x + 1];
    int ans = rmq[lg][x];
    if(level[ans] > level[rmq[lg][y - (1 << lg) + 1]])
        ans = rmq[lg][y - (1 << lg) + 1];
    return euler[ans];
}

int main() {
    fin >> n >> m;
    for(int i = 2 ; i <= n ; ++ i) {
        int x;
        fin >> x;
        g[x].push_back(i);
    }
    dfs(1, 1);
    buildrmq();
    while(m -- ) {
        int x, y;
        fin >> x >> y;
        fout << query(x, y) << '\n';
    }
    fin.close();
    fout.close();
    return 0;
}