import math 

def main() -> None:
    with open("data.csv", 'r') as data:
        vals = [int(v) for v in data]
        
        x_m = sum(vals) / len(vals)

        res = (x_m ** 3) * (math.e ** (-x_m)) 
        res = res / 6 
          
        print(res)



if __name__ == "__main__":
    main()