foo.c: In function 'main':
foo.c:6:10: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'long int *' [-Wformat=]
    6 |  scanf("%d", &M);
      |         ~^   ~~
      |          |   |
      |          |   long int *
      |          int *
      |         %ld
foo.c:15:13: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long int' [-Wformat=]
   15 |    printf("%d %d\n", i, n - 1);
      |            ~^        ~
      |             |        |
      |             int      long int
      |            %ld
foo.c:15:16: warning: format '%d' expects argument of type 'int', but argument 3 has type 'long int' [-Wformat=]
   15 |    printf("%d %d\n", i, n - 1);
      |               ~^        ~~~~~
      |                |          |
      |                int        long int
      |               %ld
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%d", &M);
      |  ^~~~~~~~~~~~~~~

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