import sys, time, random
from collections import deque, Counter, defaultdict
def debug(*x):print('debug:',*x, file=sys.stderr)
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 61 - 1
mod = 998244353

n = ii()
cnt = 0
while True:
    if cnt % 2 == 0:
        print('D', flush=True)
    else:
        print('R', flush=True)
    cnt += 1
    s = ii()
    
    if s != 0:
        exit()