#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC target ("popcnt")

using namespace std;

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

const int MAX_N = 100000;
const int MAX_M = 2000000;
int n, m, u, v;
vector<int> edge[MAX_N + 5];

int k, euler[2 * MAX_N + 5], level[2 * MAX_N + 5], first[MAX_N + 5];
inline void dfs(int crt, int lvl){
    euler[++k] = crt;
    level[k] = lvl;
    first[crt] = k;

    for(auto nxt : edge[crt]){
        dfs(nxt, lvl+1);
        euler[++k] = crt;
        level[k] = lvl;
    }
}

int lg2[2 * MAX_N + 5], rmq[18][2 * MAX_N + 5];
static inline int query(int j, int jj){
    int i = lg2[jj-j+1];
    jj -= (1<<i)-1;
    if(level[ rmq[i][j] ] < level[ rmq[i][jj] ])
        return euler[ rmq[i][j] ];
    else
        return euler[ rmq[i][jj] ];
}

int main (){
    ios_base::sync_with_stdio(false);
    fin.tie(nullptr), fout.tie(nullptr);

    fin>>n>>m;
    for(v=2; v<=n; v++){
        ///u -> v
        fin>>u;
        edge[u].push_back(v);
    }

    dfs(1, 1);

    lg2[0] = lg2[1] = 0;
    for(int i=2; i<=k; i++)
        lg2[i] = lg2[(i >> 1)] + 1;

    for(int j=1; j<=k; j++)
        rmq[0][j] = j;

    for(int i=1; i<=lg2[k]; i++)
        for(int j=1, jj; (jj = j + (1 << (i-1)))<=k; j++){
            if(level[ rmq[i-1][j] ] < level[ rmq[i-1][jj] ])
                rmq[i][j] = rmq[i-1][j];
            else
                rmq[i][j] = rmq[i-1][jj];
        }

    while(m--){
        fin>>u>>v;

        if(first[u] > first[v])
            u ^= v, v ^= u, u ^= v;

        fout<<query(first[u], first[v])<<"\n";
    }
    return 0;
}