Update app.py

app.py

@@ -33,7 +33,7 @@ def roman_calculator_converter(value1:int, value2:int, oper:str) -> str:
     }
     roman_string = ""
     
-    if oper = "add":
+    if oper == "add":
         result = value1 + value2
     elif oper == "subtract":
         result = value2 - value1