foo.c: In function 'main':
foo.c:8:12: warning: unused variable 'ch' [-Wunused-variable]
       char ch;
            ^~
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d\n",&n,&m);
  ^~~~~~~~~~~~~~~~~~~~~~
foo.c:9:7: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
       scanf("%c",&a[i][j]);
       ^~~~~~~~~~~~~~~~~~~~

Found 10 testcases.
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