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