f = open("24_5139.txt")
h = f.readline()
g = 'AEU'
s = 'BCDF'
cnt = 0
mx = 0
for i in range(2, len(h) - 1, 3):
    if h[i - 1] in s and h[i] in g and h[i + 1] in s:
        cnt += 1
    else:
        mx = max(cnt, mx)
        cnt = 0
print(max(mx, cnt))