Passing & in query string

I want to pass '&' operator in query string. I tried to use urlencode and urldecode
but its not working. I am doing this:

$abc="A & B";
 $abc2=urlencode($abc);
 

Then I am passing the value like this

<a href="hello.php?say=<?php echo $abc2 ?>"><?php echo $abc;?></a>
 

and getting value on next page as

$abc=$_GET['say'];
 $abcd=urldecode($abc');
 echo $abcd;
 

but the output is not A & B

What am I doing wrong?

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