A child is running up a staircase with N steps and can hop either 1 step, 2 steps, or 3 steps at a time. Implement a method to count how many possible ways the child can run-up to the stairs. You need to return a number of possible ways W.

#include <iostream>
using namespace std;
int staircase(int n){
    /* Don't write main().
     *  Don't read input, it is passed as function argument.
     *  Return output and don't print it.
     *  Taking input and printing output is handled automatically.
     */
    if(n==1)
        return 1;
    if(n==2)
        return 2;
    if(n==3)
        return 4;
    
    if(n>3)
    {
        return staircase(n-1)+staircase(n-2)+staircase(n-3);
    }
    
    
    
}

int main() {
    int n, output;
    cin >> n;
    output=staircase(n);
    cout<< output <<endl;
}