### Judging Olympia

Time Limit: 1000 ms Memory Limit: 65536 KiB

#### Problem Description

For years, a group of Regional Contest Directors (RCDs) of the ACM International Collegiate  Programming Contest (ICPC) have been unsatisfied with the way contest submissions get ranked.  The group sees it is academically wrong to emphasize the importance of program correctness, disregarding the “quality” of the program itself. After all, programming as a profession promotes design, style, maintainability, etc. and not just correctness. The group’s suggestion is to have a panel of six judges. Each judge is assigned the task of grading the submissions based on a particular aspect: 1) Correctness; 2) Robustness; 3) Overall design; 4) Clarity; 5) Coding style; and finally 6) Maintainability. The final grade of a submission would be the average of the six grades it gets.

#### Input

Your program will be tested on one or more test cases. Each test case is described on a single input line listing the grades of the judges. The end of the test cases is identified with a dummy test case with all the grades being zero.

#### Output

For each test case, print the grade on a separate line (without unnecessary decimal points and/or zeros.)

#### Sample Input

8 8 8 4 4 4
8 8 6 4 4 3
0 0 0 0 0 0


#### Sample Output

6
5.5