def find_change_idx(ops, idx, main_elem, elem, prev_elem):
    while idx < len(ops):
        prev_elem = elem
        elem = ops[idx]
        if elem == prev_elem and elem == main_elem:
            return idx
        idx += 1
    return idx + 1



def sort(ops):
    if len(ops) < 3:
        return 0
    prev_elem = ops[0]
    elem = ops[1]
    idx = 1
    count = 0
    length = len(ops)
    op_dict = {"+": "-", "-": "+"}
    while idx < length:
        
        if elem == prev_elem:
            change_idx = find_change_idx(ops, idx + 1, op_dict[elem], elem, prev_elem)
            ops = ops[0:idx] + ops[idx + 1:change_idx] + [ops[idx]] + ops[change_idx:]
            count += 1
            elem = ops[idx]
        idx += 1
        prev_elem = elem
        if idx < len(ops):
            elem = ops[idx]
    print(count)


def main():
    line = input()
    ops = [op for op in line]
    sort(ops)

main()