Consider the following digraph $($directed graph$)$ with $8$ vertices

$V=\{s,r,t,v,w,x,y,z\}$

and $14$ edges

$E=\{(s,w),(s,x),(s,y),(s,r),(r,v),(r,w),(r,z),(t,v),(w,z),(x,t),(y,r),(y,t),(y,v),(y,x)\}$

whose weights are given below:

weight $(s,w)=9$; weight $(s,x)=8$; weight $(s,y)=1$; weight $(s,r)=7$; weight $(r,v)=1$; weight $(r,w)=1$;

weight $(r,z)=3$;

weight $(t,v)=2$; weight $(w,z)=1$; weight $(x,t)=1$; weight $(y,r)=5$; weight $(y,t)=18$; weight $(y,v)=12$;

weight $(y,x)=3$;

Let $s$ be start vertex.

Not including the start vertex $s,$ what are the first $4$ vertices

$($in order$)$ whose distances are

determined by Djikstra's algorithm?