# 写一个函数求三个数的和,写一个函数三个数的平均值
def sum(a,b,c):
return a+b+c
def pinjun(a,b,c):
aa = sum(a,b,c)
return aa/3.0
# return (a+b+c)/3.0
i=0
sum1 = []
while i<3:
l = int(input('请输入%d个数'%(i+1)))
i+=1
sum1.append(l)
a = sum1[0]
b = sum1[1]
c = sum1[2]
print(sum(a,b,c))
print(pinjun(a,b,c))