def f_closest(number, list_of_numbers):
    list=[]

    for i in range(len(list_of_numbers)):
        x = number-list_of_numbers[i]
        if (x!=0):
            list.append(x)
    y=min(list, key=abs)
    z=list.index(y)
    v=list_of_numbers[z]
    return v
number = 10

list_of_numbers = [1,2,3,4,5,7,8,11]
closest=f_closest(number,list_of_numbers)
print(closest)