1579: Maybe bro.kun is real big dog
[Creator : ]
Description
As we all know ,bro.kun is fond of learning.And he is a gentleman,don't want his shoes so dirty.But the weather is not beautiful, the outside is a torrential rain.Learning in his mind is a matter of rain or shine.He decided to go to the classroom in the rain to learn the training of Alibaba staff.The Upper triangular region ground was filled with water. He decided to take the nearest road to the classroom.If the coordinates of his bedroom are (0,0) and the cooedinates of classroom is (n,n).And bro.kun is geniues,so he want to know how many shortest ways from bedroom to classroom by programming.If you grace as bro.kun,please prove yourself.
Input
the classroom's coordinates n
Multiple data read in
Output
the shortest ways from bedroom to classroom
Sample Input Copy
4
Sample Output Copy
14
HINT
the 14 ways are:
