#include <bits/stdc++.h>
#define N_MAX 100005
using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
int m,n,nivel[N_MAX],h[N_MAX],arb[20][N_MAX];
bool ap[N_MAX];
vector <int> lista[N_MAX];
vector <int> e;
int nr;
void dfs(int node)
{
    e.push_back(node);
    ap[node]=1;
    for(auto x:lista[node])
    {
        if(ap[x]) continue;
        nivel[x]=nivel[node]+1;
        dfs(x);
        e.push_back(node);
    }
}
void rmq()
{
    for(int i=0; i<nr; i++)
    {
        arb[0][i]=i;
    }
    int put=1;
    for(int i=1; put<nr; i++)
    {
        for(int j=0; j<nr-put; j++)
        {
            if(nivel[e[arb[i-1][j]]]>nivel[e[arb[i-1][j+put]]])
            {
                arb[i][j]=arb[i-1][j+put];
            }
            else
                arb[i][j]=arb[i-1][j];
        }
        put*=2;
    }
}
int inlog(int a)
{
    int no=0;
    while(a)
        no++,a/=2;
    return no-1;
}
int put(int a)
{
    if(a==0)
        return 1;
    if(a==1)
        return 2;
    int aux=put(a/2);
    if(a%2)
        return aux*aux*2;
    return aux*aux;
}
int lca(int x, int y)
{
    x=h[x];
    y=h[y];
    if(x>y)
        swap(x,y);
    int u=inlog(y-x+1);
    int p=put(u);
    if(nivel[e[arb[u][x]]]<nivel[e[arb[u][y-p+1]]])
        return e[arb[u][x]];
    return e[arb[u][y-p+1]];
}
int main()
{
    in >> n >> m;
    h[1]=-1;
    for(int i=2; i<=n; i++)
    {
        int x;
        in >> x;
        h[i]=-1;
        lista[x].push_back(i);
    }
    nivel[1]=1;
    dfs(1);
    nr=e.size()-1;
    for(int i=0; i<nr; i++)
    {
        if(h[e[i]]==-1)
            h[e[i]]=i;
    }
    rmq();
    for(int i=1; i<=m; i++)
    {
        int x,y;
        in >> x >> y;
        out << lca(x,y) << '\n';
    }
    return 0;
}