#include<algorithm>
#include<bitset>
#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<deque>
#include<fstream>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>

using namespace std;

#ifdef HOME
const string inputFile = "input.txt";
const string outputFile = "output.txt";
#else
const string problemName = "lca";
const string inputFile = problemName + ".in";
const string outputFile = problemName + ".out";
#endif

const int NMAX = 100000 + 5;

int N, M;
int lvl[NMAX];
int dad[NMAX];
int first[NMAX];
vector<int> V[NMAX];
int euler[2 * NMAX], cnt;
int RMQ[18][2 * NMAX];
int lg2[2 * NMAX];
int pw2[18];

void dfs(int x) {
    lvl[x] = lvl[dad[x]] + 1;
    first[x] = ++cnt;
    euler[cnt] = x;

    for(auto y : V[x]) {
        dad[y] = x;
        dfs(y);
        euler[++cnt] = x;
    }
}

void build() {
    int i, j, p;

    for(i = 1; i <= cnt; i++)
        RMQ[0][i] = euler[i];

    for(i = 1, p = 2; 1 + p / 2 <= cnt; i++, p *= 2)
        for(j = 1; j + p / 2 <= cnt; j++)
            if(lvl[RMQ[i - 1][j]] < lvl[RMQ[i - 1][j + p / 2]])
                RMQ[i][j] = RMQ[i - 1][j];
            else
                RMQ[i][j] = RMQ[i - 1][j + p / 2];

    for(i = 2; i <= cnt; i++)
        lg2[i] = lg2[i / 2] + 1;

    pw2[0] = 1;
    for(i = 1; i <= lg2[cnt]; i++)
        pw2[i] = pw2[i - 1] * 2;
}

int query(int x, int y) {
    int d = y - x + 1;
    int i = lg2[d];
    int p = pw2[i];

    if(lvl[RMQ[i][x]] < lvl[RMQ[i][y - p + 1]])
        return RMQ[i][x];
    else
        return RMQ[i][y - p + 1];
}

int lca(int x, int y) {
    x = first[x];
    y = first[y];
    return query(min(x, y), max(x, y));
}

int main() {
    int i, x, y;

#ifndef ONLINE_JUDGE
    freopen(inputFile.c_str(), "r", stdin);
    freopen(outputFile.c_str(), "w", stdout);
#endif

    scanf("%d%d", &N, &M);

    for(i = 2; i <= N; i++) {
        scanf("%d", &x);
        V[x].push_back(i);
    }

    dfs(1);
    build();

    while(M--) {
        scanf("%d%d", &x, &y);
        printf("%d\n", lca(x, y));
    }

    return 0;
}