Compilare: main.c: In function 'main': main.c:10:3: warning: suggest parentheses around assignment used as truth value [-Wparentheses] for(;r=c%d;c=d,d=r); ^~~ main.c:5:2: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("holiday.in","r",stdin),freopen("holiday.out","w",stdout),scanf("%d%d%d",&a,&b,&c); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:5:34: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("holiday.in","r",stdin),freopen("holiday.out","w",stdout),scanf("%d%d%d",&a,&b,&c); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:5:68: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("holiday.in","r",stdin),freopen("holiday.out","w",stdout),scanf("%d%d%d",&a,&b,&c); ^~~~~~~~~~~~~~~~~~~~~~~~