1 #include <iostream>
 2 #include <cstdio>
 3 
 4 using namespace std;
 5 int father[100010],n,m;
 6 
 7 int find(int a)
 8 {
 9     int flag=0;
10     while(a!=father[a])
11     {
12         a=father[a];
13         flag++;
14     }
15     return flag;
16 }
17 
18 int main ()
19 {
20     while (~scanf("%d%d",&n,&m))
21     {
22         for (int i=1; i<=n; i++)
23             father[i]=i;
24         if (n==0&&m==0)
25             break;
26         for (int i=1; i<=n-1; i++)
27         {
28             int a,b;
29             scanf("%d%d",&a,&b);
30             father[b]=a;
31         }
32         for (int i=1; i<=m; i++)
33         {
34             int startl,startp;
35             scanf("%d%d",&startl,&startp);
36             int t1=find(startl);
37             int t2=find(startp);
38             if (t1>t2)
39             printf ("pfz\n");
40             else
41             printf ("lxh\n");
42         }
43     }
44     return 0;
45 }