Compilare: user.cpp: In function ‘int main()’: user.cpp:26:50: warning: unused variable ‘nr2’ [-Wunused-variable] int nr4 = 0, nr2 = 0, r2 = 0; ^ user.cpp:10:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &a, &b); ^