



if __name__ == '__main__':
    
    dd =None
    if dd is not None:
        df=23
    if dd == None:
        df = 21
    print(df)
    
    arr ={}
    jongMok = "0506940"
    arr[jongMok]=0
    
    print(arr["05069402"])
    
    volume = ""
    if len(volume) == 0:
        volume="-1"
    print(int(volume))
