import sys
sys.setrecursionlimit(10**7)

seen={(0,0)}
dx=[0,1,0,-1]
dy=[1,0,-1,0]


def solve(x,y,d):
    seen.add((x,y))
    for _ in range(4):
        le=input()
        if le=="Merry Christmas!":
            exit()
        le=int(le)
        if not (x+dx[d],y+dy[d]) in seen:
            if le:
                print("F")
                solve(x+dx[d],y+dy[d],d)
                input()
                print("B")
        print("L")
        d+=1
        d%=4

solve(0,0,0)






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