Problems
Binomial Sum
Binomial Sum
Given a positive integer $n$. Find the value of the next sum
$$
1 \cdot C_n^{0} + 2 \cdot C_n^{1} + 3 \cdot C_n^{2} + ... + (n + 1) \cdot C_n^{n}
$$
\InputFile
One positive integer $n\:(n \le 30)$.
\OutputFile
Print the sum value.
Input example #1
3
Output example #1
20