Compilare: user.cpp: In function ‘int main()’: user.cpp:51: warning: operation on ‘Co’ may be undefined user.cpp:53: warning: operation on ‘Co’ may be undefined user.cpp:24: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result