Compilare: main.cpp: In function 'int main()': main.cpp:27:17: warning: unused variable 'j' [-Wunused-variable] long long i,j,a,b; ^ main.cpp:25:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("tarabe.in","r",stdin); ^ main.cpp:26:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("tarabe.out","w",stdout); ^ main.cpp:29:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld",&n,&k); ^ main.cpp:32:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld",&b,&a); ^