text: S = input()
  
  N = len(S) + 1
  t = [0] * N
  for i in range(N - 1):
      if S[i] == '<':
          t[i + 1] = t[i] + 1
  for i in range(N - 2, -1, -1):
      if S[i] == '>':
          t[i] = max(t[i], t[i + 1] + 1)
  print(sum(t))
  