TETTHET_GULL = 19.32
TETTHET_JERN = 7.87
TETTHET_VANN = 0.997

def main():
    data = []
    while True:
        x = input('give a number [q to quit]: ')
        if x == 'q':
            break
        else:
            data.append(int(x))
    mtrl = get_material()
    result = calculate_masse(mtrl,data)
    print(f"Masse er {result}")  

def get_material():
    while True:
        material = input("Velg material: [g]ull [j]ern [v]ann: ")
        if material in 'gjv':
            return material
        else:
            print("velg bare g eller j eller v")

def calculate_masse(material,data):
    volum = 1
    for i in data:
        volum *= i

    if material == 'g':
        masse = TETTHET_GULL * volum
    elif material == 'j':
        masse = TETTHET_JERN * volum
    else: 
        masse = TETTHET_VANN * volum
    return masse

 
main()