S = input()

if 'A' in S :
    S = S.replace('B', 'A')
    S = S.replace('C', 'A')
    S = S.replace('D', 'A')
    S = S.replace('F', 'A')
elif 'B' in S :
    S = S.replace('C', 'B')
    S = S.replace('D', 'B')
    S = S.replace('F', 'B')
elif 'C' in S :
    S = S.replace('D', 'C')
    S = S.replace('F', 'C')
else :
    S = 'A'*len(S)

print(S)