#include<stdio.h>
int run(int n)
{
if(((n%4==0)&&(n%100!=0))||(n%400==0))
return 1;
else
return 0; //闰年为真,否则为假
}
int main()
{
int year,month,day;
int flag=0;
scanf("%d%d%d",&year,&month,&day);
if((year>=1912)&&(year<=2019))
{if(month<13&&month>0)
{
if((month=1)||(month==3)||(month==5)||(month==7)||(month==8)||(month==10)||(month==12))
if((day>0)&&(day<=31))
flag=1;
if((month==4)||(month==6)||(month==9)||(month==11))
if((day>0)&&(day<=30))
flag=1;
if((month=2)&&(run(year))&&(day>0)&&(day<=29))
flag=1;
if((month=2)&&(!run(year))&&(day>0)&&(day<=28))
flag=1;
}
}
if(flag)
printf("OK");
else
printf("NO");
return 0;
}