foo.c: In function 'main':
foo.c:7:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld",&n);
  ^~~~~~~~~~~~~~~~
foo.c:28:14: warning: 'm' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if(nn==0) m=m+2;
             ~^~~~

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