def solution(s):
    result = 0
    count = 0
    for c in s:
        if c == '>':
            count += 1
        if c == '<':
            result += count
    return 2 * result

tests = [
        (">----<", 2),
        ("<<>><", 4),
        ("--->-><-><-->-", 10),
        ]

for i, o in tests:
    result = solution(i)
    print (i, result == o, result, o)