Compilare: main.cpp: In function 'int main()': main.cpp:16:35: warning: variable 'kv' set but not used [-Wunused-but-set-variable] long long n , k ,zt , zv , kt , kv; ^~ main.cpp:17:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pif.in" , "r" , stdin); ^ main.cpp:18:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pif.out" , "w" , stdout); ^ main.cpp:19:48: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%lld%lld" , &n , &k, &zv, &zt); ^