Problem E
Pizza Cutting
Input:standard input
Output: standard output
When someone calls Ivan
lazy, he claims that it is his intelligence that helps him to be so. If his
intelligence allows him to do something at less physical effort, why should he
exert more? He also claims that he always uses his brain and tries to do some
work at less effort; this is not his laziness, rather this is his intellectual
smartness.
Once Ivan was asked to cut a pizza into seven pieces to distribute it
among his friends. (Size of the pieces may not be the same. In fact, his piece
will be larger than the others.) He thought a bit, and came to the conclusion
that he can cut it into seven pieces by only three straight cuts through the
pizza with a pizza knife. Accordingly, he cut the pizza in the following way
(guess which one is Ivan's piece):
One of his friends, who
never believed in Ivan’s smartness, was startled at this intelligence. He
thought, if Ivan can do it, why can’t my computer? So he tried to do a similar
(but not exactly as Ivan's, for Ivan will criticize him for stealing his idea)
job with his computer. He wrote a program that took the number of straight cuts
one makes through the pizza, and output a number representing the maximum number
of pizza pieces it will produce.
Your job here is to write a
similar program. It is ensured that Ivan’s friend won’t criticize you for doing
the same job he did.
Input
The input file will contain
a single integer N (0 <= N <= 210000000) in each line representing the number of
straight line cuts one makes through the pizza. A negative number terminates the
input.
Output
Output the maximum number of pizza pieces the given number of cuts can produce. Each line should contain only one output integer without any leading or trailing space.
Sample Input:
5
Sample Output:
16