Compilare: user.cpp: In function ‘int main()’: user.cpp:19:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("classictask.in", "r", stdin); ^ user.cpp:20:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("classictask.out", "w", stdout); ^ user.cpp:22:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld %lld ", &a, &b, &c); ^