/in/foo.c:1:1: warning: data definition has no type or storage class
 a = list(map(int, input().split(',')))
 ^
/in/foo.c:1:1: warning: type defaults to 'int' in declaration of 'a' [-Wimplicit-int]
/in/foo.c:1:5: warning: implicit declaration of function 'list' [-Wimplicit-function-declaration]
 a = list(map(int, input().split(',')))
     ^~~~
/in/foo.c:1:10: warning: implicit declaration of function 'map' [-Wimplicit-function-declaration]
 a = list(map(int, input().split(',')))
          ^~~
/in/foo.c:1:14: error: expected expression before 'int'
 a = list(map(int, input().split(',')))
              ^~~
/in/foo.c:2:1: error: expected ',' or ';' before 'b'
 b = 0
 ^
/in/foo.c:17:7: warning: multi-character character constant [-Wmultichar]
 print('%.1f' % b)
       ^~~~~~