toys.cpp: In function 'int main()': toys.cpp:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result toys.cpp:30: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result toys.cpp: In function 'void ReadData()': toys.cpp:93: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result toys.cpp:94: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result