#include <fstream>
#include <queue>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int d[100001],val[100001*2],p[100001*2],t,l,b;
pair<int,int> niv[20][100001*2];
vector<int> v[100001];
int i,n,a,m,nr;

void dfs(int nod, int ni)
{
    d[nod]=++nr;niv[0][nr].first=ni,niv[0][nr].second=nr;val[nr]=nod;
    for(int i=0;i<v[nod].size();i++)
    {
        dfs(v[nod][i], ni+1);
        niv[0][++nr].first=ni,niv[0][nr].second=nr,val[nr]=nod;
    }
}

int main()
{
    fin>>n>>m;
    for(i=2;i<=n;i++)
    {
        fin>>a;
        v[a].push_back(i);
    }
    dfs(1, 0);
    for(i=2;i<=nr;i++)
        p[i]=p[i/2]+1;
    for(t=1;t<=p[nr];t++)
    {
        for(i=1;i<=nr;i++)
        {
            niv[t][i]=niv[t-1][i];
            if (i+(1<<(t-1))<=nr)
                if(niv[t][i].first>niv[t-1][i+(1<<(t-1))].first)
                    niv[t][i]=niv[t-1][i+(1<<(t-1))];
        }
    }
    for(i=1;i<=m;i++)
    {
        fin>>a>>b;a=d[a];b=d[b]; if(a>b) swap(a,b);
        l=p[b-a+1];
        if(niv[l][a].first<niv[l][b-(1<<l)+1].first)
            fout<<val[niv[l][a].second]<<"\n";
        else
            fout<<val[niv[l][b-(1<<l)+1].second]<<"\n";
    }
    return 0;
}