minor fix

Co-authored-by: Andrii Siriak <[email protected]>

Author: albina-astr

src/main/java/com/thealgorithms/maths/Factorial.java

@@ -9,7 +9,7 @@ public class Factorial {
      */
     public static long factorial(int n) {
         if (n < 0) {
-            throw new IllegalArgumentException("Input number cannot be negative!");
+            throw new IllegalArgumentException("Input number cannot be negative");
         }
         long factorial = 1;
         for (int i = 1; i <= n; ++i) {