#include <bits/stdc++.h>
#define Nmax 100005
using namespace std;
ifstream fin ("lca.in");
ofstream fout ("lca.out");

vector <int> v[Nmax];

int n, l[Nmax], p[Nmax], t[Nmax], i, j, x, y, m, h, H;
void dfs(int x)
{
    int i;
    for(i=0;i<v[x].size();i++)
    {
        l[v[x][i]]=l[x]+1;
        H=max(H, l[v[x][i]]);
        dfs(v[x][i]);
    }
}
void tata(int x)
{
    if(l[x]<h)
        p[x]=1;
    else if(l[x]%h==0)
        p[x]=t[x];
    else
        p[x]=p[t[x]];
    int i;
    for(i=0;i<v[x].size();i++)
        tata(v[x][i]);
}
int intrebare(int x, int y)
{
    while(p[x]!=p[y])
        if(l[x]>l[y])
            x=p[x];
        else y=p[y];

    while(x!=y)
        if(l[x]>l[y])
            x=t[x];
        else y=t[y];

    return x;
}
int main()
{
    fin >> n >> m;
    for(i=2;i<=n;i++)
        {
            fin >> t[i];
            v[t[i]].push_back(i);
        }
    dfs(1);
    h=sqrt(H);
    tata(1);
    for(i=1;i<=m;i++)
    {
        fin >> x >> y;
        fout << intrebare(x, y) << '\n';
    }
    return 0;
}