How to count the number of section tags in an article tag?

I have been trying to write code that would use an embedded for loop to calculate the number of sections inside of each article (there is more than one so I can't use getID) in a document. When the button is clicked the code works but the numbers it calculates are completely off which means something isn't counting correctly. Here is my function:

<script>

   function Calculations() {
        var a = document.getElementsByTagName("article");
        var s = 0;
        var z = 0;
        var x;
        for (x = 0; x < a.length; x++) {
            var cn = a[x].childNodes;
            z++
            for (i = 0; i < cn.length; i++) {
                if (cn[i].nodeType == 1) {
                    if (cn[i].tagName == "P"); {
                        s++;
                    }
                }
            }
            alert("Article " + z + " has " + s + " section.")
            s = 0              
        }
        alert("There are " + a.length + " total articles.")
    }
</script>

Thank you so much for your help!