Given N, write a program to count the number of ways to express N as sum of 1, 3 and 4.

Example 1

Input: N = 4
Output: 4 
Explanation: 1+1+1+1 
             1+3
             3+1 
             4 

Example 2

Input: N = 5 
Output: 6
Explanation: 1 + 1 + 1 + 1 + 1
             1 + 4
             4 + 1
             1 + 1 + 3
             1 + 3 + 1
             3 + 1 + 1