import sys
sys.setrecursionlimit(200000)


s = input()
num = len(s)
ans = 0

def count(pos, befor, co):
  global ans
  if pos >= num:
    if ans < co:
      ans = co
    return True
  
  for p in range(1, 3):
    if ans > co + len(s[pos+p:]) + 1:
      break
    if s[pos:pos+p] != befor:
      a = count(pos + p, s[pos:pos+p], co+1)
      
        

  return True

ans = 0

a = count(0, "", 0)
print(ans)
