/in/foo.c: In function 'main':
/in/foo.c:6:11: warning: format '%ld' expects argument of type 'long int *', but argument 2 has type 'long long int *' [-Wformat=]
  scanf("%ld", &n);
           ^
/in/foo.c:18:12: warning: format '%ld' expects argument of type 'long int', but argument 2 has type 'long long int' [-Wformat=]
  printf("%ld", n);
            ^
/in/foo.c:17:13: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
  n = n * 10 + t;
      ~~~~~~~^~~