  InterviewBit Academy is now Scaler Academy! # Vowels

You are given an Integer N.

You have to find how many different strings of length N can be made using Vowels (a, e, i, o, u) only and by following given rules :

‘a’ can only be followed by ‘e’ and ‘i’.

‘e’ can only be followed by ‘i’.

‘i’ can only be followed by ‘a’, ‘e’, ‘o’, and ‘u’.

‘o’ can only be followed by ‘a’ and ‘u’.

‘u’ can only be followed by ‘o’ and ‘e’.

for example N = 2

``````strings starting with 'a' of length 2 are:
1. "ae"
2. "ai"
strings starting with 'e' of length 2 are:
1. "ei"
strings starting with 'i' of length 2 are:
1. "ia"
2. "io"
3. "iu"
4. "ie"
strings starting with 'o' of length 2 are:
1. "oa"
2. "ou"
strings starting with 'u' of length 2 are:
1. "uo"
2. "ue"

so total number of strings can be made using vowels and following above rules will be 11.
``````

Input Format

``````Given the only argument N of type Integer.
``````

Output Format

``````Return a single Integer X mod (1e9 + 7), i.e number of Strings that can be made using vowels and following above rules.
``````

Constraints

``````1 <= N <= 1e5
strings will have only lowercase letters.
``````

Example

``````Example Input:
N = 1

Example Output:
5

Explanation:
Strings of length 1 are :
1. "a"
2. "e"
3. "i"
4. "o"
5. "u"

Example Input:
N = 2

Example Output:
11

Explanation:
as explained above.
``````
NOTE: You only need to implement the given function. Do not read input, instead use the arguments to the function. Do not print the output, instead return values as specified. Still have a doubt? Checkout Sample Codes for more details. 