PROGRAMMING:Grade (*)

Please write a program to determine the grade of students according to their scores.
```
Grade
[90, 100] A
[80, 90) B
[70, 80) C
[60, 70) D
[0, 60) E
```
####Input format
>Achievements
####Output format
>Grade
####Input sample
```in
eighty-seven point five
```
####Output sample
```out
B
```







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