Problem with defining a function

[snippsat]

You are running all code in interactive shell(>>>).
You need to open a New File window,look at this .
Then whole code need to be without >>>.
You save eg grades.py and Run with F5.

counter = 0
PassCounter = 0
FailCounter = 0
Average = 0
#This function does the calculations
def Calc(): 
    MidGrade = int(input("Your mid-term grade is: "))
    print (str(MidGrade) + "%")
    FinGrade = int(input("Your Final grade is: "))
    print (str(FinGrade) + "%")
    WeightedMid = MidGrade*.4
    WeightedFin = FinGrade*.6
    global Average
    Average = WeightedMid + WeightedFin
 
#This function outputs the necessary information  
def Output():
    print ("Your Average is: " + str(Average) + "%")
    counter = + 1
    if Average > 59.99:
        print ("You have passed the course!")
        global PassCounter
        PassCounter = + 1
    else:
        print ("You have failed the course.")
        global FailCounter
        FailCounter = + 1
    print ("Number of grades calculated: " + str(counter))
    print ("Number of students who have passed: " + str(PassCounter))
    print ("Number of students who have failed: " + str(FailCounter))
 
print (Calc())
print (Output())

I may come back with suggestion to fix stuff that are not good in this code.