// 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 the stairs.

class RunningSteps {

public static void main(String arg[]) {

RunningSteps s = new RunningSteps();

int n = 4;

System.out.println(s.count(n));

}

int count (int n) {

int count = 0;

if (n == 1) {

count = 1;

}

if (n == 2) {

count = 2;

}

if (n == 3) {

count = 4;

}

if (n > 3) {

count = count(n - 1) + count(n - 2) + count(n - 3);

}

return count;

}

}