22c22
<     const x: usize = 1;
---
>     var x: usize = 1;
26c26
<     // 'undefined'. There is no problem on this line.
---
>     // 'undefined'. There is no error here.
36c36
<     lang[???] = letters[x];
---
>     lang[1] = letters[x];
38,39c38,39
<     x = ???;
<     lang[2] = letters[???];
---
>     x = 5;
>     lang[2] = letters[x];