#include <iostream> #include <stdio.h> using namespace std; #define Max 100001 int father[Max]; void Init() { int i; for(i=0;i<Max;++i) father[i]=i; } int Findfather(int x) { int count=0; while (x!=father[x]) { count++; x=father[x]; } return count; } void Union(int x,int y) { father[y]=x; } int main() { int n,m,x,y,i,t1,t2; while (scanf("%d%d",&n,&m),n&&m) { Init(); for(i=0;i<n-1;++i) { scanf("%d%d",&x,&y); Union(x,y); } for(i=0;i<m;++i) { scanf("%d%d",&x,&y); t1=Findfather(x); t2=Findfather(y); if(t1<=t2) printf("lxh\n"); else { printf("pfz\n"); } } } }