/in/foo.cc: In function 'void dfssolve(int, int)':
/in/foo.cc:77:25: warning: integer overflow in expression [-Woverflow]
   long long ac=(1ll<<63)-1;
                ~~~~~~~~~^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:103:18: warning: integer overflow in expression [-Woverflow]
   dp[i]=(1ll<<63)-1;
         ~~~~~~~~~^~