foo.cc: In function 'int main()':
foo.cc:41:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
foo.cc:42:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i=1;i<=n;i++) scanf("%d",&dk[i]);
                           ~~~~~^~~~~~~~~~~~~
foo.cc:45:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&e[i][0],&e[i][1]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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