백준) 2754번 - python

a = input()
grade = {
    "A+": 4.3,
    "A0": 4.0,
    "A-": 3.7,
    "B+": 3.3,
    "B0": 3.0,
    "B-": 2.7,
    "C+": 2.3,
    "C0": 2.0,
    "C-": 1.7,
    "D+": 1.3,
    "D0": 1.0,
    "D-": 0.7,
    "F" : 0.0
}

if a in grade.keys(): print(grade[a])