#include <bits/stdc++.h>

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
const int Nmax=1e5+5;
vector<int> v[Nmax];
int depth[Nmax];
int dp[3*Nmax][50];
int poz[Nmax];
vector<int> e;
vector<int> l;
int lca(int a,int b)
{
    int i=poz[a],j=poz[b];
    if(i>j) swap(i,j);
    int siz=(j-i+1);
    int k=log2(siz);
    ///if(a==18 && b==19) cout<<i<<' '<<j<<' '<<siz<<' '<<k<<'\n';
    int fhalf=l[dp[i][k]],shalf=l[dp[j-(1<<k)+1][k]];
    if(fhalf<=shalf) return e[dp[i][k]];
    else return e[dp[j-k+1][k]];
}
void dfs(int nod,int prev)
{
    e.push_back(nod);
    l.push_back(depth[nod]);
    poz[nod]=e.size()-1;
    for(auto u:v[nod])
    {
        if(u!=prev)
        {
            depth[u]=depth[nod]+1;
            dfs(u,nod);
            e.push_back(nod);
            l.push_back(depth[nod]);
        }
    }
    return;
}
int main()
{
    int n,m;
    fin>>n>>m;
    for(int i=1;i<n;i++)
    {
        int x;
        fin>>x;
        v[x].push_back(i+1);
        v[i+1].push_back(x);
    }
    dfs(1,0);
    int k=log2(e.size());
    for(int i=0;i<e.size();i++)
    {
        dp[i][0]=i;
        ///cout<<e[i]<<' ';
    }
    ///cout<<'\n';
    for(int j=1;j<=k;j++)
    {
        for(int i=0;i<e.size();i++)
        {
            int fhalf=l[dp[i][j-1]],shalf=l[dp[i+(1<<(j-1))][j-1]];
            if(fhalf<=shalf) dp[i][j]=dp[i][j-1];
            else dp[i][j]=dp[i+(1<<(j-1))][j-1];
            ///cout<<i<<' '<<j<<' '<<dp[i][j]<<'\n';
        }
    }
   /// cout<<'\n';
    while(m--)
    {
        int a,b;
        fin>>a>>b;
        fout<<lca(a,b)<<'\n';
    }
    return 0;
}