import sys
import math
from itertools import product, permutations, combinations, accumulate
from heapq import heapify, heappush, heappop
from collections import deque, defaultdict, Counter
from bisect import bisect, bisect_left, bisect_right
from copy import copy, deepcopy
#from sortedcontainers import SortedSet, SortedList, SortedDict

sys.setrecursionlimit(10**7)
INF = float('inf')
LINF = 1 << 60
MOD = 10**9+7

def mii():
    return map(int, sys.stdin.readline().split())

S = input()
N = len(S)


st = deque()
cut = 0
cur = 0
now = 0

for i in range(N):
    c = S[i]
    if c == "<":
        st.append(i - cur)
    elif c == ">":
        if len(st) == 0:
            continue
        if (i - cur - now) - st[-1] >= 2:
            now = (i - cur) - st[-1] + 1
            st.pop()
        else:
            st.clear()
            cut += now
            cur = i

cut += now

print(N - cut)