foo.c: In function 'main':
foo.c:19:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(i>=3)
  ^~
foo.c:21:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   for(j=3;j<=i;++j)
   ^~~
foo.c:10:6: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
      scanf("%d",&i);
      ^~~~~~~~~~~~~~

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