my_dict = {
    'a':50, 
    'b':58, 
    'c':56,
    'd':40, 
    'e':100, 
    'f':20
    }
list=[]
i=0
max1=0
max2=0
max3=0
for key in my_dict:
    for value in my_dict:
        if my_dict[key]>max1:
            max1=my_dict[key]
        elif max1>my_dict[value]and max2<my_dict[value]:
            max2=my_dict[value]
        elif max2>my_dict[value]and max3<my_dict[value]:
            max3=my_dict[value]
list.append(max1)
list.append(max2)
list.append(max3)
print(list)
    

