# import sys
# input = sys.stdin.readline
def mp():return map(int,input().split())
def lmp():return list(map(int,input().split()))
def mps(A):return [tuple(map(int, input().split())) for _ in range(A)]
import math
import bisect
import heapq
from copy import deepcopy as dc
from itertools import accumulate
from collections import Counter, defaultdict, deque
def ceil(U,V):return (U+V-1)//V
def modf1(N,MOD):return (N-1)%MOD+1
inf = int(1e20)
mod = int(1e9+7)
import time
import copy

s = input()
if s in "ACDFG":
    print(s+"#")
elif s == "E":print("F")
else:print("C")