subgeom.cpp: In function 'void read()': subgeom.cpp:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result subgeom.cpp:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result subgeom.cpp: In function 'int main()': subgeom.cpp:81: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result subgeom.cpp:82: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result subgeom.cpp:84: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result