#include <iostream>
#include <vector>
#include <algorithm>
#include <limits>
#include <numeric>
#include <cstring>
#include <string>
#include <queue>
#include <set>
#include <cmath>
#include <fstream>
#include <cstdlib>
#include <map>
#define pb push_back
#define mp make_pair
#define INF numeric_limits<int>::max()
#define bit(x) (-x)&x
#define int64 long long
using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
vector< vector<int> > a;
vector<int> p,eul,lvl;
int n,k;
void dfs(int x,int level)
{
    lvl[++k]=level;
    eul[k]=x;
    p[x]=k;
    for(vector<int>::iterator i=a[x].begin();i!=a[x].end();i++)
    {
        dfs(*i,level+1);
        lvl[++k]=level;
        eul[k]=x;
    }
}
int RMQ[20][250000],lg[250000];
void rmq()
{
    for(int i=1;i<=k;i++)
    {
        if(i>=2)
            lg[i]=lg[i/2]+1;
        RMQ[0][i]=i;
    }
    for(int i=1;(1<<i)<=k;i++)
    for(int j=1;j<=k-(1<<i)+1;j++)
        RMQ[i][j]=( lvl[ RMQ[i-1][j] ] > lvl[ RMQ[i-1][j+(1<<(i-1))] ] ? RMQ[i-1][j+(1<<(i-1))] : RMQ[i-1][j] );
}
int LCA(int x,int y)
{
    x=p[x];
    y=p[y];
    if(x>y)
        swap(x,y);
    int diff=y-x+1;
    return (lvl[ RMQ[lg[diff]][x] ]  > lvl[ RMQ[lg[diff]][x+diff-(1<<lg[diff])] ] ? eul[ RMQ[lg[diff]][x+diff-(1<<lg[diff])] ] : eul[ RMQ[lg[diff]][x] ]);
}
int main()
{
    int q;
    in>>n>>q;
    a=vector< vector<int> > (n+1);
    p=vector<int> (n+1);
    lvl=eul=vector<int> (2*n+2);
    for(int i=2;i<=n;i++)
    {
        int x;
        in>>x;
        a[x].pb(i);
    }
    dfs(1,1);
    rmq();
    for(;q;q--)
    {
        int x,y;
        in>>x>>y;
        out<<LCA(x,y)<<'\n';
    }
    return 0;
}