Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:39: error: ‘mod’ was not declared in this scope user.cpp:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:40: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result