/in/foo.c:3:1: error: expected identifier or '(' before '{' token
 {
 ^
/in/foo.c: In function 'C':
/in/foo.c:49:3: warning: implicit declaration of function 'hanoit' [-Wimplicit-function-declaration]
   hanoit(n - 1, a, c, b);
   ^~~~~~
/in/foo.c: In function 'R':
/in/foo.c:61:9: warning: 'return' with a value, in function returning void
  return 0;
         ^
/in/foo.c:56:6: note: declared here
 void R()
      ^