/in/foo.c:3:1: warning: data definition has no type or storage class
 a=int(input())
 ^
/in/foo.c:3:1: warning: type defaults to 'int' in declaration of 'a' [-Wimplicit-int]
/in/foo.c:3:3: error: expected expression before 'int'
 a=int(input())
   ^~~
/in/foo.c:9:7: warning: multi-character character constant [-Wmultichar]
 print('%.4f'%d)
       ^~~~~~