sub.cpp: In function 'int main()': sub.cpp:92: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sub.cpp:93: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sub.cpp:94: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sub.cpp:95: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sub.cpp:104: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sub.cpp:110: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sub.cpp:113: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result