The balloon is used to prove that you solve the problem in the competition.One day, the careless fishfloss accidentally released a balloon, the balloon was affected by the air flow floating in the air.Now he gives you a string containing only the letters 'u' and 'd', which represent the balloon going up and down respectively.Assuming that the base distance up or down is 1. So let's figure out how far the balloon is moving.
输入描述:
One line,a string containing only letters 'u' and 'd'.
(0 < the string's length < 64 )
输出描述:
Output one line ,a number about the answer.