foo.c: In function 'main':
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
foo.c:16:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   16 |    scanf("%d", &a[i][j]);
      |    ^~~~~~~~~~~~~~~~~~~~~
foo.c:32:23: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
   32 |     if (a[i][0] > a[k][0])
      |                   ~~~~^~~

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