PROGRAMMING:series
There is a column of numbers: 1, 1, 3, 8, 22, 60164448... The first three numbers are 1, 1, 3. From the fourth number, each number is twice the sum of the first two numbers. Then, you can easily get the k-th number in the sequence.
30% data, 1 < = k < = 8
100% data, 1 < = k < = 45
###Input format:
There is only one row and one number k, which means that what you want to ask is the k-th number in the sequence.
###Output format:
There is only one row and one number n, indicating that the value of the kth number in the sequence is n.
###Input example:
```in
five
```
###Output example:
```out
twenty-two
```
answer:If there is no answer, please comment
30% data, 1 < = k < = 8
100% data, 1 < = k < = 45
###Input format:
There is only one row and one number k, which means that what you want to ask is the k-th number in the sequence.
###Output format:
There is only one row and one number n, indicating that the value of the kth number in the sequence is n.
###Input example:
```in
five
```
###Output example:
```out
twenty-two
```
answer:If there is no answer, please comment