foo.c: In function 'main':
foo.c:12:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(k=z;k<=a*b;k++);
  ^~~
foo.c:13:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  {
  ^
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&a,&b);
  ^~~~~~~~~~~~~~~~~~~

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