#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
using namespace std;
class lca
{
    vector<vector<int>>rmq;
    vector<int>e,poz,h,lg;
    int n;
public:
    void dfs(vector<vector<int>>&a,int nod,int tata)
    {
        h[nod]=h[tata]+1;
        poz[nod]=(int)e.size();
        e.push_back(nod);
        for(auto c:a[nod])
        {
            if(c==tata)continue;
            dfs(a,c,nod);
            e.push_back(nod);
        }
    }
    void dfs(vector<vector<int>>&a)
    {
        dfs(a,1,1);
    }
    int maxx(int x,int y)
    {
        if(h[x]>h[y])return y;
        return x;
    }
    void build_rmq()
    {
        for(int i=1;i<=n;i++)
        {
            rmq[i][0]=e[i];
        }
        for(int j=1;(1<<j)<=n;j++)
        {
            for(int i=1;i+(1<<j)-1<=n;i++)
            {
                rmq[i][j]=maxx(rmq[i][j-1],rmq[i+(1<<(j-1))][j-1]);
            }
        }
    }
    lca(vector<vector<int>>&a)
    {
        n=(int)a.size()-1;
        poz.resize(n+1);
        h.resize(n+1);
        h[1]=0;
        e={0};
        dfs(a);
        n=(int)e.size()-1;
        lg.resize(n+1);
        lg[1]=lg[0]=0;
        for(int i=2;i<=n;i++)
        {
            lg[i]=lg[i/2]+1;
        }
        rmq=vector<vector<int>>(n+1,vector<int>(lg[n]+2));
        build_rmq();
    }
    int get_lca(int x, int y)
    {
        int l=poz[x],r=poz[y];
        if(r<l)
        {
            swap(l,r);
        }
        int lung=lg[r-l+1];
        return maxx(rmq[l][lung],rmq[r-(1<<lung)+1][lung]);
    }

};
int main()
{
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    int n,q;
    cin>>n>>q;
    vector<int>val(n+1,0);
    for(int i=1;i<=n;i++)
    {
        //cin>>val[i];
    }
    vector<vector<int>>a(n+1);
    for(int i=2;i<=n;i++)
    {
        int x,y;
        //cin>>x>>y;
        cin>>x;
        a[x].push_back(i);
        //a[y].push_back(x);
    }
    lca tree(a);
    int x,y;
    while(cin>>x>>y)
    {
        cout<<tree.get_lca(x,y)<<'\n';
    }
}