Compilare: user.c: In function ‘main’: user.c:6:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("paralelograme.in","r",stdin),freopen("paralelograme.out","w",stdout),scanf("%d%d",&n,&m); ^ user.c:6:50: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("paralelograme.in","r",stdin),freopen("paralelograme.out","w",stdout),scanf("%d%d",&n,&m); ^ user.c:6:88: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("paralelograme.in","r",stdin),freopen("paralelograme.out","w",stdout),scanf("%d%d",&n,&m); ^