foo.c: In function 'main':
foo.c:7:6: warning: unused variable 'x' [-Wunused-variable]
  int x=0;
      ^
foo.c:8:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&m,&n);
  ^~~~~~~~~~~~~~~~~~~
foo.c:12:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&a[i][j]);
    ^~~~~~~~~~~~~~~~~~~~
foo.c:34:7: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
    cnt++;
    ~~~^~

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