foo.c: In function 'main':
foo.c:11:12: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
   11 |    scanf("%d",a[i][j]);
      |           ~^  ~~~~~~~
      |            |      |
      |            int *  int
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%d%d",&m,&n);
      |  ^~~~~~~~~~~~~~~~~~~
foo.c:11:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   11 |    scanf("%d",a[i][j]);
      |    ^~~~~~~~~~~~~~~~~~~

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