#include <iostream>
#include <fstream>
#include <cstring>
#include <vector>

using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");

#define ll long long
#define pb push_back
const int NMax = 1e5 + 5;
const int eulerMax = 4*NMax;

int N,M,nrEuler;
bool vis[NMax];
int dad[NMax],idx[NMax],depth[NMax],euler[eulerMax],rmq[eulerMax][20],lg[eulerMax];
vector<int> v[NMax];

void dfs(int,int);

int main() {
    in>>N>>M;
    for (int i=2;i<=N;++i) {
        int dad;
        in>>dad;

        v[dad].pb(i);
    }

    dfs(1,1);

    lg[1] = 0;
    rmq[1][0] = euler[1];
    for (int i=2;i <= nrEuler;++i) {
        lg[i] = lg[i/2] + 1;
        rmq[i][0] = euler[i];
    }

    for (int p=1; (1<<p) <= nrEuler; ++p) {

        for (int i=1;i + (1<<p) <= nrEuler;++i) {
            int node1 = rmq[i][p-1],
                node2 = rmq[i+(1<<(p-1))][p-1];
            if (depth[node1] < depth[node2]) {
                rmq[i][p] = node1;
            }
            else {
                rmq[i][p] = node2;
            }
        }
    }

    while (M--) {
        int a,b;
        in>>a>>b;

        a = idx[a];
        b = idx[b];
        if (a > b) {
            swap(a,b);
        }

        int pw = lg[b-a+1],
            node1 = rmq[a][pw],
            node2 = rmq[b-(1<<pw)+1][pw];
        if (depth[node1] < depth[node2]) {
            out<<node1<<'\n';
        }
        else {
            out<<node2<<'\n';
        }
    }

    in.close();out.close();
    return 0;
}

void dfs(int node,int dep) {
    vis[node] = true;
    euler[++nrEuler] = node;
    idx[node] = nrEuler;
    depth[node] = dep;

    for (auto nxt : v[node]) {
        if (vis[nxt]) {
            continue;
        }

        dfs(nxt,dep+1);
        euler[++nrEuler] = node;
    }
}