foo.c:2:1: warning: return type defaults to 'int' [-Wimplicit-int]
    2 | Shan(int a[500][500],int m,int n)
      | ^~~~
foo.c: In function 'main':
foo.c:23:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   23 |  scanf("%d %d\n",&m,&n);
      |  ^~~~~~~~~~~~~~~~~~~~~~
foo.c:27:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   27 |   scanf("%d",&a[i][j]);
      |   ^~~~~~~~~~~~~~~~~~~~

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