Problem:
Score : 300 points

Problem Statement

Given is a string S of length N-1.
Each character in S is < or >.

A sequence of N non-negative integers, a_1,a_2,\cdots,a_N, is said to be good when the following condition is satisfied for all i (1 \leq i \leq N-1):

If S_i= <: a_i<a_{i+1}

If S_i= >: a_i>a_{i+1}

Find the minimum possible sum of the elements of a good sequence of N non-negative integers.

Constraints

2 \leq N \leq 5 \times 10^5

S is a string of length N-1 consisting of < and >.

Input

Input is given from Standard Input in the following format:

S

Output

Find the minimum possible sum of the elements of a good sequence of N non-negative integers.

Sample Input 1

<>>

Sample Output 1

3

a=(0,2,1,0) is a good sequence whose sum is 3.
There is no good sequence whose sum is less than 3.

Sample Input 2

<>>><<><<<<<>>><

Sample Output 2

28

Solution in Python (3.4.3) (judge verdict: Wrong Answer)

def p(num):
  # 変数初期化
  count = 1
  result = ''
  max_count = 0
	# 配列全体のループ
  for i in range(len(num)):
    try:
        if num[i] == num[i+1]:
           count = count + 1
        else:
            result = result + str(num[i]) + str(count)
            if max_count < count:
              max_count = count
            count = 1
    except:
          # 最後の文字セットがOutOfRangeになるので結果に出力
          result = result + str(num[i]) + str(count)
  return result, max_count

S = input()
S, _ = p(S)
pre = 0
count =0
for i in range(int(len(S)/2)):

  if S[i*2] == ">":
    n = int(S[i*2+1])
    sum_ = int(n*(n+1)/2)
    count += sum_

    
    count -= min(pre,n)
 
  elif S[i*2] == "<":
    n = int(S[i*2+1])
    sum_ = int(n*(n+1)/2)
    count += sum_
    pre = n


print(count)