```
public class Solution
{
    public int jumpFloor(int target)
    {
        int f[] = new int[40 + 10];
        f[1] = 1;
        f[2] = 2;
        for (int i = 3; i <= target; i++)
            f[i] = f[i - 1] + f[i - 2];
        return f[target];
    }
}

```