flood.cpp: In function 'void read()': flood.cpp:49: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result flood.cpp:50: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result flood.cpp:56: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result flood.cpp:65: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result flood.cpp:67: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result