#include <fstream>
#include <vector>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
const int NMax = 100000;
vector <int> G[NMax + 5];
int V[2* NMax + 5],First[2 * NMax + 5], Level[2*NMax  + 5],Log[2*NMax + 5];
int RMQ[21][2 * NMax + 5];
int N,M;
void Read()
{
    fin >> N >> M;
    for(int i = 2; i <= N; ++i)
    {
        int x; fin >> x;
        G[x].push_back(i);
    }
}

void DFS(int Nod, int level)
{
    V[++V[0]] = Nod;
    Level[V[0]] = level;
    First[Nod] = V[0];
    for(auto Vecin : G[Nod])
    {
        DFS(Vecin,level + 1);
        V[++V[0]] = Nod;
        Level[V[0]] = level;
    }
}

void RangeMinimumQuery()
{
    for(int i = 2; i <= V[0]; ++i)
        Log[i] = Log[i/2] + 1;
    for(int i = 1; i <= V[0]; ++i)
        RMQ[0][i] = i;
    for(int i = 1; (1<<i) <= V[0]; ++i)
        for(int j = 1; j <= V[0] - (1<<i) + 1; ++j)
        {
            if(Level[RMQ[i-1][j + (1<<(i-1))]] < Level[RMQ[i-1][j]])
                RMQ[i][j] = RMQ[i-1][j+(1<<(i-1))];
            else
                RMQ[i][j] = RMQ[i-1][j];
        }
}

int LCA(int x, int y)
{
    int index;
    x = First[x]; y = First[y];
    if(y<x) swap(x,y);
    int k = y-x+1;
    k = Log[k];
    if(RMQ[k][x] < RMQ[k][y - (1<<k) + 1])
        index = RMQ[k][x];
    else
        index = RMQ[k][y - (1<<k) + 1];
    return V[index];
}
int main()
{
    Read();
    DFS(1,0);
    RangeMinimumQuery();
    while(M--)
    {
        int x,y;
        fin >> x >> y;
        fout << LCA(x,y) << "\n";
    }
    return 0;
}