import sys sys.setrecursionlimit(10**7) N=int(input()) seen={(0,0)} def solve(x,y): seen.add((x,y)) le=input() if le=="Merry Christmas!": exit() le=int(le) if not (x+1,y) in seen: if le: print("F") solve(x+1,y) input() print("B") print("L") le=input() if le=="Merry Christmas!": exit() le=int(le) if not (x,y+1) in seen: if le: print("F") solve(x,y+1) input() print("B") print("L") le=input() if le=="Merry Christmas!": exit() le=int(le) if not (x-1,y) in seen: if le: print("F") solve(x-1,y) input() print("B") print("L") le=input() if le=="Merry Christmas!": exit() le=int(le) if not (x,y-1) in seen: if le: print("F") solve(x,y-1) input() print("B") print("L") print("F") solve(0,0)