S=input()
from collections import deque
d=deque();nd=deque()

for s in S:
  d.append(s)
  f=0
  while d:
    if f==0:
      if d[-1]=='>':
        c=d.pop()
        nd.appendleft(c)
        f=1 
      else:
        break 
    elif f==1:
      if d[-1]=='=':
        c=d.pop()
        nd.appendleft(c)
        f=2
      else:
        break 
    elif f==2:
      if d[-1]=='=':
        c=d.pop()
        nd.appendleft(c) 
      elif d[-1]=='<':
        c=d.pop()
        nd.appendleft(c) 
        f=3
        break 
      else:
        break 
  if f!=3:
    while nd:
      c=nd.popleft()
      d.append(c)
  else:
    nd=deque()
print(len(d))