#include <fstream>
#include <vector>
using namespace std;
#define dim 100005

vector<int> v[dim];
int E[dim * 2];
int L[dim * 2];
int H[dim];
int rmq[2*dim][20];
int currIdx = 0;
int currLvl = -1;

int min(int a,int b)
{
    if(a > b)
        return b;
    return a;
}

void dfs(int node,int father)
{
    E[++currIdx] = node;
    L[currIdx] = ++currLvl;
    if(H[node] == 0)
        H[node] = currIdx;

    int N = v[node].size();
    for(int i = 0; i < N; i++)
    {
        if(v[node][i] != father)
        {
            dfs(v[node][i],node);
            E[++currIdx] = node;
            L[currIdx] = --currLvl;
        }
    }
}

void precompute_RMQ(int rmq[][20])
{
    for(int i = 1; i <= currIdx; i++)
        rmq[i][0] = i;

    for(int i = 1; (1 << i) <= currIdx; i++)
    {
        for(int j = 1; j + (1 << i) - 1 <= currIdx; j++)
        {
            int mid = j + (1 << (i-1));
            rmq[j][i] = rmq[mid][i-1];
            if(L[rmq[j][i-1]] < L[rmq[mid][i-1]])
                rmq[j][i] = rmq[j][i-1];
        }
    }
}

int RMQ(int l,int r)
{
    int p = 0;
    for(;(1 << p) <= r - l + 1; p++);
    p--;
    int mid = r - (1 << p) + 1;
    if(L[rmq[l][p]] < L[rmq[mid][p]])
        return rmq[l][p];
    return rmq[mid][p];
}

int LCA(int x,int y)
{
    if(H[x] > H[y])
    {
        int aux = x;
        x = y;
        y = aux;
    }
    return E[RMQ(H[x],H[y])];
}


int main()
{
    ifstream fin("lca.in");
    ofstream fout("lca.out");

    int n,m;
    fin >> n >> m;

    for(int i = 1; i < n; i++)
    {
        int x;
        fin >> x;
        v[x].push_back(i+1);
        v[i+1].push_back(x);
    }

    dfs(1,-1);

    precompute_RMQ(rmq);

    for(int i = 1; i <= m; i++)
    {
        int x,y;
        fin >> x >> y;
        fout << LCA(x,y) << "\n";
    }
}