#python 3.9 Version
#python.exe -m pip install --upgrade pip

# mod1.py
def add(a,b) :
    return a+b

def sub(a,b) :
    return a - b

# python mod1.py 로 했을때만 동작함
if __name__ == "__main__":
    print(add(1,4))
    print(sub(4,2))


