file = open('19.txt')
s = file.readline()
l = 0
kt = 0
ans = 0
for r in range(1, len(s)):
    if s[r] == 'T':
        kt += 1
    while kt >= 100:
        if s[l] == 'T':
            kt -= 1
        l += 1
    ans = max(ans, r - l + 1)
print(ans)