foo.cc:5:5: error: expected initializer before ‘int’
    5 |     int out=0
      |     ^~~
foo.cc:12:5: error: expected unqualified-id before ‘return’
   12 |     return out;
      |     ^~~~~~
foo.cc:13:1: error: expected declaration before ‘}’ token
   13 | }
      | ^
foo.cc: In function ‘int main()’:
foo.cc:18:15: error: ‘fan’ was not declared in this scope
   18 |         cout<<fan(in)<<endl;
      |               ^~~