题解 | #牛牛的绩点#
牛牛的绩点
https://www.nowcoder.com/practice/de8bc3e736164786b07a4dd64ed172f7
d = {"A": 4, "B": 3, "C": 2, "D": 1, "F": 0} # 绩点
s = input()
num1 = 0
num2 = 0
while s != "False":
s1 = int(input())
num1 += d[s] * s1 # 绩点和
num2 += s1 # 学分和
s = input()
print("%.2f" % (num1 / num2))
