foo.cc:3:14: error: ISO C++ forbids declaration of 'l' with no type [-fpermissive]
    3 | l(int a,int b)
      |              ^
foo.cc:7:14: error: ISO C++ forbids declaration of 's' with no type [-fpermissive]
    7 | s(int a,int b)
      |              ^

[Hydro](https://hydro.ac)提供评测服务