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 fishfloss gives you a string containing only the letters u and d, which represent the balloon going up and down,
respectively.It's different from the last competition that this balloon is so amazing, every time you do the same operation
continuously,
it goes up or down twice as far, assuming that the base distance up or down is 1.
So let's figure out how far the balloon is moving.