Compilare: user.cpp: In function ‘int euler(int)’: user.cpp:66: warning: no return statement in function returning non-void user.cpp: In function ‘int main()’: user.cpp:70: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:71: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:74: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result