foo.cc: In function 'int main()':
foo.cc:32:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
foo.cc:34:32: 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%d",&p[i].x,&p[i].y);
                           ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:36:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&e[i].u,&e[i].v);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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