def main():
    S = input()
    decided = []
    stack = []
    for letter in S:
        if not stack:
            if letter == "<":
                stack.append(letter)
                continue
            decided.append(letter)
            continue

        match stack[-1]:
            case "=":
                if letter in ("=", "<"):
                    stack.append(letter)
                    continue
                if letter == ">":
                    while stack[-1] in ("=", "<"):
                        popped = stack.pop()
                        if popped == "<":
                            break
                    continue
            case "<":
                if letter in ("<", "="):
                    stack.append(letter)
                    continue
                if letter == ">":
                    decided.append(letter)
                    decided.extend(stack)
                    stack.clear()
                    continue
            case _:
                raise ValueError
    print(len(stack) + len(decided))


if __name__ == "__main__":
    main()