file = open('26.txt')
s = file.readline()
x = 'DBAC'
ans = 0
while x in s:
    ans = len(x)
    x += 'DBAC'
x = x[:-4]
if x + 'D' in s:
    ans += 1
if x + 'DB' in s:
    ans += 1
if x + "DBA" in s:
    ans += 1
print(ans)