Undefined and how to initialiaze this var

Tell us what’s happening:
i am stock i need help with this pleaseeeeee

Your code so far

// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";

var a=6;
var b=15;
 var ="I am a string!";

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User Agent is: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

Link to the challenge:

Pay attention to the comments here. Your code also has a syntax error.

Let me know if this helps

Why are you trying to redefine a, b, and c here?

Do you understand the difference between just declaring a variable and initializing a variable?

You are only supposed to change the first three lines of code. Do not add any code at the bottom like you did.

The previous lesson explains how to initialize a variable.