cai.cpp: In function 'int main()': cai.cpp:59: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cai.cpp:60: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cai.cpp:61: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cai.cpp:72: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cai.cpp:81: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result