Add new file

plate.py

@@ -0,0 +1,12 @@
+def main():
+    plate = input("Plate: ")
+    if is_valid(plate):
+        print("Valid")
+    else:
+        print("Invalid")
+        
+def is_valid(s):
+    s = s.upper()
+    return s == "CS50"
+
+main()