Compilare: main.c: In function 'main': main.c:7:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("ndiv.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:8:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("ndiv.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:11:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld", &a, &b); ^~~~~~~~~~~~~~~~~~~~~~~~~~