/in/foo.c: In function 'main':
/in/foo.c:4:2: error: unknown type name 'Int'
 {Int n;
  ^~~
/in/foo.c:5:3: error: 'cin' undeclared (first use in this function)
   cin>>n;cout<<1;
   ^~~
/in/foo.c:5:3: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:5:10: error: 'cout' undeclared (first use in this function)
   cin>>n;cout<<1;
          ^~~~