There are $6$ stairs, and you can walk for one or three staris each time. There are~\uline{~~~~~~~~~~}~different ways to walk the $6$ stairs. 
Overseas Competition->Knowledge Point->Counting Modules
$$\left( 1,1,1,1,1,1 \right)$$；$$\left( 3,1,1,1 \right)$$；$$\left( 1,3,1,1 \right)$$；$$\left( 1,1,3,1 \right)$$；$$\left( 1,1,1,3 \right)$$；$$\left( 3,3 \right)$$． 