materom.cpp: In function 'int main()': materom.cpp:18: warning: unused variable 'k' materom.cpp:18: warning: unused variable 'st' materom.cpp:18: warning: unused variable 'dr' materom.cpp:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result materom.cpp:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result materom.cpp:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result materom.cpp:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result