foo.c:1:1: warning: data definition has no type or storage class
 a = int(input())
 ^
foo.c:1:1: warning: type defaults to 'int' in declaration of 'a' [-Wimplicit-int]
foo.c:1:5: error: expected expression before 'int'
 a = int(input())
     ^~~

[Hydro](https://hydro.ac)提供评测服务