Compilare: user.cpp: In function ‘int main()’: user.cpp:28:23: warning: unused variable ‘l’ [-Wunused-variable] int r=0,a,b,c,d,e,l; ^ user.cpp:26:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("eqs.in","r",stdin); ^ user.cpp:27:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("eqs.out","w",stdout); ^ user.cpp:29:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d",&a,&b,&c,&d,&e); ^