Fix typo in stock variable name for Walmart in main.py

main.py

@@ -106,7 +106,7 @@ while daysleft > -1:
                 if microsoft >= amountinput:
                     microsoft = microsoft - amountinput
             elif stockinput == 4:
-                if walmrt >= amountinput:
+                if walmart >= amountinput:
                     walmart = walmart - amountinput
             elif stockinput == 5:
                 if car >= amountinput: