uscat.cpp: In function 'int main()': uscat.cpp:48: warning: unused variable 'm' uscat.cpp:48: warning: unused variable 'k' uscat.cpp:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result uscat.cpp:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result uscat.cpp:49: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result uscat.cpp:52: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result uscat.cpp:55: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result