Compilare: main.c: In function 'main': main.c:59:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:60:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:64:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^~~~~~~~~~~~~~~~~~~~~~ main.c:66:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^~~~~~~~~~~~~~~~~~~~~~