Grades

During the term each student writes three tests.
For each test, the student receives a mark
(a natural number greater than or equal to zero
and smaller than or equal to 100).  The first 
test is worth 20%, the second one 30% and the
final one 50%.  We need your help with computing
the weighted average (given as a real number greater 
than or equal to zero and smaller than or equal 
to 100 with two digits precision).

Input

The input consists of a single line.  The line
consists of three natural number greater than or 
equal to zero and smaller than or equal to 100.
The numbers are separated by a single space.

Output

The output consists of a single line.  The
line consists of a a real number greater
than or equal to zero and smaller than or equal
to 100 with two digits precision.

Sample Input

100 80 60

Sample Output

74.00