secvop.cpp: In function 'int main()': secvop.cpp:46: warning: comparison between signed and unsigned integer expressions secvop.cpp:75: warning: comparison between signed and unsigned integer expressions secvop.cpp:111: warning: comparison between signed and unsigned integer expressions secvop.cpp:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result secvop.cpp:30: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result secvop.cpp:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result secvop.cpp:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result