#include <bits/stdc++.h>
#include <fstream>
#define cin fin
#define cout fout
using namespace std;
ifstream cin("lca.in");
ofstream cout("lca.out");
vector<int>G[100008];
int v[400008],poz[100008],nvl[100008],m,n,x,cnt,i,j,a,b,aux;
struct element
{
    int val,nod;
};
element dp[30][400008];
void dfs(int nod,int nvl2)
{
    nvl[nod]=nvl2;
    v[++cnt]=nod;
    poz[nod]=cnt;
    for(auto i:G[nod])
    {
        if(nvl[i]==0)
        {
            dfs(i,nvl2+1);
            v[++cnt]=nod;
        }
    }
}
int main()
{
    cin>>n>>m;
    for(i=2;i<=n;i++)
    {
        cin>>x;
        G[x].push_back(i);
    }
    dfs(1,1);
    for(i=1;i<=cnt;i++)
    {
        dp[0][i].val=nvl[v[i]];
        dp[0][i].nod=v[i];
    }
    for(i=1;(1<<i)<=cnt;i++)
    {
        for(j=1;j<=cnt-(1<<i)+1;j++)
        {
            if(dp[i-1][j].val>dp[i-1][j+(1<<(i-1))].val)
            {
                dp[i][j]=dp[i-1][j+(1<<(i-1))];
            }
            else
            {
                dp[i][j]=dp[i-1][j];
            }
        }
    }
    for(i=1;i<=m;i++)
    {
        cin>>a>>b;
        a=poz[a];
        b=poz[b];
        if(a>b)
            swap(a,b);
        aux=(int)(log2(b-a+1));
        if(dp[aux][a].val>dp[aux][b-(1<<aux)+1].val)
            cout<<dp[aux][b-(1<<aux)+1].nod;
            else
            cout<<dp[aux][a].nod;
        cout<<'\n';
    }
    return 0;
}