harta2.cpp: In function 'int main()': harta2.cpp:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result harta2.cpp:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result harta2.cpp:13: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result harta2.cpp:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result harta2.cpp:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result harta2.cpp:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result harta2.cpp:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result