#include <cstdio>
#include <vector>

using namespace std;

#define logMAX 20
#define NMAX 100005

int N,Q,cnt;
vector < pair < int , int > > pair_Euler;
vector < int > L[NMAX];
int first[NMAX];
int Lg[NMAX*2];
int RMQ[logMAX][NMAX*4];

void Read()
{
    int i,X;

    scanf("%d%d",&N,&Q);

    for (i=2;i<=N;++i)
    {
        scanf("%d",&X);
        L[X].push_back(i);
    }
}

int LCA(int X,int Y)
{
    int X_position=first[X];
    int Y_position=first[Y];

    if (X_position>Y_position)
    swap(X_position,Y_position);

    int sol=RMQ[Lg[Y_position-X_position+1]][X_position];

    if (pair_Euler[sol].second > pair_Euler[RMQ[Lg[Y_position-X_position+1]][Y_position+1-(1<<(Lg[Y_position-X_position+1]))]].second)
    sol=RMQ[Lg[Y_position-X_position+1]][Y_position+1-(1<<(Lg[Y_position-X_position+1]))];

    return pair_Euler[sol].first;

}

void Euler(int nod,int nivel)
{
    vector < int > :: iterator it;

    pair_Euler.push_back(make_pair(nod,nivel));
    first[nod]=++cnt;

    for (it=L[nod].begin();it!=L[nod].end();++it)
    {
        Euler(*it,nivel+1);

        pair_Euler.push_back(make_pair(nod,nivel));
        ++cnt;
    }

}

void buildRMQ()
{
    int i,j;

    for (i=2,RMQ[0][1]=1;i<=cnt;++i)
    {
        Lg[i]=Lg[i/2]+1;
        RMQ[0][i]=i;
    }

    for (i=1;(1<<i)<cnt;++i)
       for (j=1;j<=cnt-(1<<i);++j)
    {
        RMQ[i][j]=RMQ[i-1][j];

        if (pair_Euler[RMQ[i-1][j+(1<<(i-1))]].second>=pair_Euler[RMQ[i][j]].second)
        continue;

        RMQ[i][j]=RMQ[i-1][j+(1<<(i-1))];
    }
}

void Solve()
{
    int X,Y;

    while (Q--)
    {
        scanf("%d%d",&X,&Y);
        printf("%d\n",LCA(X,Y));
    }
}

int main()
{
freopen("lca.in","r",stdin);
freopen("lca.out","w",stdout);

pair_Euler.push_back(make_pair(0,0));
Read();
Euler(1,0);
buildRMQ();
Solve();

return 0;
}