foo.cc: In function 'int main()':
foo.cc:42:23: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context]
           b[i][j][k]=1<<30;
                      ~^~~~
foo.cc:38:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d\n",&n,&m,&d);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~

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