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Per works at the KTH Royal Institute of Technology, and thus grades a lot of exams each day.

The grading process is rather simple. First, you define five grading limits $a$, $b$, $c$, $d$ and $e$. At least $a \%$ of the exam score is required to get an A grade, at least $b \%$ is required for a B, and so on, and $e \%$ is required to get an E. If you get less than $e \%$ you get an F.

Per’s management has recently complained about a lot of mistakes that Per made during grading, so they want you to construct a program to help Per grade exams.

## Input

The first line of the input contains the five integers $a$, $b$, $c$, $d$ and $e$ ($100 \ge a > b > c > d > e \ge 0$).

The second line contains a single integer – the exam score in percent of an exam Per is currently grading.

## Output

Output a single letter A-F – the grade of the exam Per is currently grading.

Sample Input 1 Sample Output 1
90 89 70 60 50
40

F

Sample Input 2 Sample Output 2
100 99 98 97 96
97

D