reinvent.cpp: In constructor 'InputReader::InputReader(const char*)': reinvent.cpp:11: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result reinvent.cpp: In constructor 'InputReader::InputReader(const char*)': reinvent.cpp:11: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result reinvent.cpp: In constructor 'InputReader::InputReader(const char*)': reinvent.cpp:11: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result reinvent.cpp: In member function 'void InputReader::advance()': reinvent.cpp:33: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result reinvent.cpp: In function 'int bfs()': reinvent.cpp:58: warning: control reaches end of non-void function