moves = input().strip()
cups = [True, False, False]

for move in moves:
    if move == "A":
        cups[0], cups[1] = cups[1], cups[0]
    elif move == "B":
        cups[1], cups[2] = cups[2], cups[1]
    elif move == "C":
        cups[0], cups[2] = cups[2], cups[0]

print(cups.index(True) + 1)