Unable to complete task because of error

Tell us what’s happening:
Describe your issue in detail here.
why does it shows error as “you should not change the below code”

Your code so far

// Only change code below this line
var a=5;
var b=10;
var c="I am a";
// Only change code above this line

a = 5+ 1;
b = 10+ 5;
c = "I am a String!";

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.64 Safari/537.36 Edg/101.0.1210.47

Challenge: Understanding Uninitialized Variables

Link to the challenge:

It shows that error because you made changes in a part of the code where you were told not to make any changes.