diff --git a/learnc/learnc13.c b/learnc/learnc13.c
index 3e59dd8..8212f93 100755
--- a/learnc/learnc13.c
+++ b/learnc/learnc13.c
@@ -1,25 +1,25 @@
-#include <stdio.h>
-
-int factorial(int x);
-
-int main() {
-    /* testing code */
-    printf("0! = %i\n", factorial(0));
-    printf("1! = %i\n", factorial(1));
-    printf("3! = %i\n", factorial(3));
-    printf("5! = %i\n", factorial(5));
-}
-
-/* define your function here (don't forget to declare it) */
-int factorial(int x) {
-    
-    if (x == 0) {
-        
-        return 1;
-    } else if (x >= 1) {
-
-        return x*factorial(x-1);
-    }
-    
-    return 0;
+#include <stdio.h>
+
+int factorial(int x);
+
+int main() {
+    /* testing code */
+    printf("0! = %i\n", factorial(0));
+    printf("1! = %i\n", factorial(1));
+    printf("3! = %i\n", factorial(3));
+    printf("5! = %i\n", factorial(5));
+}
+
+// define your function here (don't forget to declare it)
+int factorial(int x) {
+    
+    if (x == 0) {
+        
+        return 1;
+    } else if (x >= 1) {
+
+        return x*factorial(x-1);
+    }
+    
+    return 0;
 }
\ No newline at end of file