#include <fstream>
#include <vector>
#include <cmath>
#define NMAX 100002
using namespace std;
ifstream  fin("lca.in");
ofstream fout("lca.out");
int n,m,H,nivel[NMAX],tata[NMAX],T2[NMAX];
vector<int> tree[NMAX];
void citire()
{
    fin>>n>>m;

    for(int i=2; i<=n; i++)
    {
        fin>>tata[i];
        tree[tata[i]].push_back(i);
    }
}

void DF(int nod, int t2, int level)
{
    nivel[nod]=level;
    T2[nod]=t2;
    if(nivel[nod]%H==0)
    {
        t2=nod;
    }

    for(int i=0; i<tree[nod].size(); i++)
    {
        int next_nod=tree[nod][i];
        DF(next_nod,t2,level+1);
    }
}

int lca(int x, int y)
{
    while(T2[x]!=T2[y])
    {
        if(nivel[x]>nivel[y])
        {
            x=T2[y];
        }
        else
        {
            y=T2[x];
        }
    }

    if(nivel[y]>nivel[x])
    {
        swap(x,y);
    }

    while(nivel[x]!=nivel[y])
    {
        x=tata[x];
    }

    while(x!=y)
    {
        x=tata[x];
        y=tata[y];
    }

    return x;
}

int main()
{
    citire();

    H=sqrt(n);
    DF(1,0,0);

    int a,b;
    for(int i=1; i<=m; i++)
    {
        fin>>a>>b;
        fout<< lca(a,b) << "\n";
    }

    return 0;
}