Record Case Detail - VE280 SU2019 (Weikang and Paul) - JOJ

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terminate called after throwing an instance of 'std::logic_error'
  what():  basic_string::_M_construct null not valid

Your answer may be identical to the JOJ answer in the first several lines.

However, the main problem you meet now is Runtime Error. And the exit code of your program is -6, which should be 0.

Please double check your code to solve this problem and try again.

Initial state
____ ____ ____ ho_w ____ 
____ fl_e ____ ____ ____ 
rr_n ____ ____ ____ ____ 
____ ____ fo_s ____ ____ 
____ ____ ____ ____ fl_s

Error: Species unknown not found!