#include <cstdio>
#include <cmath>
#include <vector>
#include <algorithm>

using namespace std;

#define NMAX 100005
#define NMAX2 200005
#define LogNMAX2 20
#define minim(a,b) ((a<b)?(a):(b))
#define Enode first
#define Edepth second

int N,Q;
int FirstInEuler[NMAX];
int SparseTable[NMAX2][LogNMAX2];

vector < int > G[NMAX];
vector < pair < int , int > > Euler;

void DFS(int node, int depth)
{
    Euler.push_back(make_pair(node,depth));
    FirstInEuler[node] = Euler.size() - 1;

    for(vector < int > :: iterator it = G[node].begin(); it != G[node].end(); ++it)
    {
        DFS(*it,depth+1);
        Euler.push_back(make_pair(node,depth));
    }
}

void ContructRMQ()
{
    for(int i=1;i<Euler.size();i++)
        SparseTable[i][0] = i;

    int i,j,minUntilNowPos,minOnSecondSegmentPos;

    for(j=1; (1<<j) <Euler.size(); j++)
        for(i=1;i + (1<<j) <= Euler.size();i++)
        {
            minUntilNowPos = SparseTable[i][j-1];
            minOnSecondSegmentPos = SparseTable[i + (1<<(j-1))][j-1];

            if(Euler[minUntilNowPos].Edepth<=Euler[minOnSecondSegmentPos].Edepth)
                SparseTable[i][j] = minUntilNowPos;
            else
                SparseTable[i][j] = minOnSecondSegmentPos;
        }
}

int LCA(int i, int j)
{
    int x,y;

    x = FirstInEuler[i];
    y = FirstInEuler[j];

    if(x>y)
        swap(x,y);

    int k = (int) log2(double(y-x+1));

    int minOnFirstSegmentPos,minOnSecondSegmentPos;

    minOnFirstSegmentPos = SparseTable[x][k];
    minOnSecondSegmentPos = SparseTable[y - (1<<k) + 1][k];

    if(Euler[minOnFirstSegmentPos].Edepth <= Euler[minOnSecondSegmentPos].Edepth)
        return Euler[minOnFirstSegmentPos].Enode;
    return Euler[minOnSecondSegmentPos].Enode;
}

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

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

    int x,y;

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

    Euler.push_back(make_pair(0,0));
    DFS(1,0);

    ContructRMQ();

    for(int i=1;i<=Q;i++)
    {
        scanf("%d%d",&x,&y);
        printf("%d\n",LCA(x,y));
    }

    return 0;
}