def check(ret):
    if ret == "20151224":
        while ret == "20151224":
            print("F", flush=True)
            ret = input()
    if ret == "Merry Christmas!":
        exit()

while 1:
    print("R",flush=True)
    ret=input()
    check(ret)
    while ret=="0":
        print("L",flush=True)
        ret=input()
        check(ret)
    print("F",flush=True)
    ret = input()
    check(ret)