perspic.cpp: In function 'int cmmmc()': perspic.cpp:66: warning: unused variable 'o' perspic.cpp: In function 'int main()': perspic.cpp:80: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result perspic.cpp:81: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result perspic.cpp:83: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result perspic.cpp:91: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result perspic.cpp:99: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result perspic.cpp:105: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result perspic.cpp:111: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result