foo.cc: In function 'int main()':
foo.cc:5:13: warning: overflow in implicit constant conversion [-Woverflow]
 #define INF (long long)(1e18)
             ^~~~~~~~~~~~~~~~~
foo.cc:15:29: note: in definition of macro '_add'
 #define _add(x,y,v) add(x,y,v),add(y,x,0)
                             ^
foo.cc:63:14: note: in expansion of macro 'INF'
   _add(x,n+1,INF);
              ^~~
foo.cc:57:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d",&x,&y,&z);
   ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:62:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x);
   ~~~~~^~~~~~~~~

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