#include <fstream>
#include <vector>
#define DIM 100005

using namespace std;

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

int n,m,i,j,x,y,k,v[DIM],euler[2*DIM],nivel[2*DIM],first[DIM];
int d[20][2*DIM],p[2*DIM];
vector<int> L[DIM];

void dfs(int nod, int niv)
{
    v[nod] = 1; euler[++k] = nod; nivel[k] = niv; first[nod] = k;
    for (int i=0; i<L[nod].size(); i++)
    {
        int vecin = L[nod][i];
        if (!v[vecin])
            dfs(vecin, niv+1);
        euler[++k] = nod; nivel[k] = niv;
    }
}

int main()
{
    fin >> n >> m;
    for (i=2; i<=n; i++)
    {
        fin >> x;
        L[x].push_back(i);
    }
    dfs(1, 1); p[1] = 0; d[0][1] = 1;
    for (i=2; i<=k; i++)
    {
        p[i] = p[i/2]+1;
        d[0][i] = i;
    }
    for (i=1; i<=p[k]; i++)
        for (j=1; j<=k; j++)
        {
            d[i][j] = d[i-1][j];
            if (j+(1<<(i-1)) <= k && nivel[d[i][j]] > nivel[d[i-1][j+(1<<(i-1))]])
                d[i][j] = d[i-1][j+(1<<(i-1))];
        }
    for (;m--;)
    {
        fin >> x >> y;
        int poz1 = first[x]; int poz2 = first[y];
        if (poz1 > poz2)
            swap(poz1, poz2);
        int l = p[poz2-poz1+1]; int minim = 0;
        if (nivel[d[l][poz1]] < nivel[d[l][poz2-(1<<l)+1]])
            minim = d[l][poz1];
        else
            minim = d[l][poz2-(1<<l)+1];
        fout << euler[minim] << "\n";
    }
    return 0;
}