#include <iostream>
#include <cstdio>
#include <vector>
#include <cmath>
using namespace std;
int n,m,adancime[100005],first[100005],rmq[50][300005];
bool viz[100005];
vector <int> G[100005];
vector <int> eulerList;
void parcurgereEuler(int nod)
{
    viz[nod]=1;
    eulerList.push_back(nod);
    for(auto fiu:G[nod])
    {
        if(!viz[fiu])
        {
            parcurgereEuler(fiu);
            eulerList.push_back(nod);
        }
    }
}
void buildrmq()
{
    for(int i=1; i<=eulerList.size(); i++)
        rmq[0][i]=eulerList[i-1];
    for(int i=1; i<=log2(eulerList.size()); i++)
        for(int j=1; j+(1<<(i-1))<=eulerList.size(); j++)
        {
            if(adancime[rmq[i-1][j]]<=adancime[rmq[i-1][j+(1<<(i-1))]])
                rmq[i][j]=rmq[i-1][j];
            else
                rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
        }
}
int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    scanf("%d%d",&n,&m);
    int tata;
    for(int i=2; i<=n; i++)
    {
        scanf("%d",&tata);
        G[tata].push_back(i);
        adancime[i]=1+adancime[tata];
    }
    parcurgereEuler(1);
    buildrmq();
    for(int i=0; i<eulerList.size(); i++)
        if(!first[eulerList[i]])
            first[eulerList[i]]=i+1;


    int st,dr;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&st,&dr);
        st=first[st];
        dr=first[dr];
        if(st>dr)
            swap(st,dr);
        int rasp,lint=log2(dr-st+1);

        if(adancime[rmq[lint][st]]<adancime[rmq[lint][dr-(1<<lint)+1]])
            rasp=rmq[lint][st];
        else
            rasp=rmq[lint][dr-(1<<lint)+1];
        printf("%d\n",rasp);
    }

    return 0;
}