Execution time limit is 1 second

Runtime memory usage limit is 128 megabytes

The integer is "Good" if it consists of only odd digits. For example the number $157953$ is good, and the number $2452117$ is not good. Find out how many $n$ - digit good numbers exist.

One positive integer $n(1≤n≤20)$.

Print the number of good integers.

Input #1

Answer #1