## DMOPC '19 Contest 7 P0 - Contest Feedback

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Points: 3
Time limit: 2.0s
Memory limit: 64M

Author:
Problem types

A certain contest with 4 problems has just finished running! As one of the problem setters, Mimi is interested in knowing what contestants thought of the problems.

After surveying everyone, she realizes that people rated the first problem an average of out of 10, the second problem out of 10, the third out of 10, and the fourth out of 10.

Mimi then wants to know:

• What was the average rating of problems 1 and 2?
• What was the average rating of problems 1 and 3?
• What was the average rating of problems 1 and 4?
• What was the average rating of problems 2 and 3?
• What was the average rating of problems 2 and 4?
• What was the average rating of problems 3 and 4?
• What was the average rating of problems 1, 2, and 3?
• What was the average rating of problems 1, 2, and 4?
• What was the average rating of problems 1, 3, and 4?
• What was the average rating of problems 2, 3, and 4?
• What was the average rating of all the problems?

As Mimi is busy setting next year's contest, this task falls to you. Can you answer Mimi's queries?

#### Input Specification

The input will consist of 4 space separated integers, , respectively.

These integers satisfy .

#### Output Specification

The answer to each query, each on a separate line.

Your answer will be judged as correct if it is within an absolute error of .

#### Sample Input

1 2 3 4

#### Sample Output

1.500000
2.000000
2.500000
2.500000
3.000000
3.500000
2.000000
2.333333
2.666667
3.000000
2.500000