/in/foo.cc: In function 'void Dij()':
/in/foo.cc:82:12: warning: unused variable 'l' [-Wunused-variable]
  int ans=0,l=0;
            ^
/in/foo.cc: In function 'bool check()':
/in/foo.cc:64:33: warning: iteration 100009 invokes undefined behavior [-Waggressive-loop-optimizations]
  for(int i=1;i<=N;i++) d[i]=h[i]=0;
                             ~~~~^~
/in/foo.cc:64:15: note: within this loop
  for(int i=1;i<=N;i++) d[i]=h[i]=0;
              ~^~~