cmmmc.cpp: In function 'int main()': cmmmc.cpp:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cmmmc.cpp:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cmmmc.cpp:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cmmmc.cpp:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cmmmc.cpp:30: warning: 'dr' may be used uninitialized in this function cmmmc.cpp:30: warning: 'st' may be used uninitialized in this function