grouping and adding form values

Hi, I would like to know if there's a way to quickly collect and sort form data, then use that data in an if statement. I've tried for a while now and i just can't seem to figure it out.

I would like to do this with radio buttons. Hopefully this will make it clear:

<?php

if (isset($_POST['submit'])) 
{
// I don't know how to do this but maybe something like

// if $_POST values == "Yes"
// put them into an array
// then count how many are in the array, e.g. 2 if 2 "Yes" radio buttons are selected

$count = count($array) . " Yes values selected";
echo $count;

//else if do the same for "No" values

// hopefully this is understandable
}

?>

<!-- i want to take these values and group them, so all the "Yes" values selected together and the "no" values together -->
<form method="post" action="">

<input type="radio" name="first" value="Yes" /> 
<input type="radio" name="first" value="No" /> 

<input type="radio" name="second" value="Yes" /> 
<input type="radio" name="second" value="No" /> 

<input type="submit" name="submit">
</form>

Code (markup):