#include<fstream>
#include<vector>
using namespace std;
vector<int> L[200005];
int n, m, d[18][200005], first[200005], nrd, fiu, q[200005], p, i, j, x, y;
void construct(int nod)
{
    d[0][++nrd]=nod;
    if(first[nod]==0)
    {
        first[nod]=nrd;
    }
    for(int i=0; i<L[nod].size(); i++)
    {
        int fiu=L[nod][i];
        construct(fiu);
        d[0][++nrd]=nod;
    }
}
ifstream in("lca.in");
ofstream out("lca.out");
int main()
{
    in>>n>>m;
    for(i=2; i<=n; i++)
    {
        in>>x;
        L[x].push_back(i);
    }
    construct(1);
    for(i=2; i<=nrd; i++)
    {
        q[i]=1+q[i/2];
    }
    for(i=1; (1<<i)<=nrd; i++)
    {
        for(j=1; j<=nrd; j++)
        {
            d[i][j]=min(d[i-1][j], d[i-1][j+(1<<(i-1))]);
        }
    }
    for(i=1; i<=m; i++)
    {
        in>>x>>y;
        if(first[x]>first[y])
            swap(x, y);
        p=q[first[y]-first[x]];
        out<<min(d[p][first[x]], d[p][first[y]-(1<<p)+1])<<"\n";
    }
    return 0;
}