/in/foo.c: In function 'FindiMax':
/in/foo.c:12:9: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return r;
         ^
/in/foo.c: In function 'main':
/in/foo.c:20:2: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",FindiMax(n,a));
  ^~~~~~~~~~~~~~~~~~~~~~~~~~