Compilare: main.c: In function 'main': main.c:15:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("nc.in","r",stdin),freopen("nc.out","w",stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:15:32: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("nc.in","r",stdin),freopen("nc.out","w",stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:17:9: warning: ignoring return value of 'fgets', declared with attribute warn_unused_result [-Wunused-result] fgets(s,4005,stdin); ^~~~~~~~~~~~~~~~~~~