#include<cstdio>
#include<cmath>
int main()
{
int x,y,flag = 0;
while(scanf("%d%d",&x,&y),x||y)
{
flag = 1;
for(int i = x;i<=y;++i)
{
int t = i*i+i+41,j;
for(j = 2;j <= int(sqrt(t));++j)
if(t%j == 0)
{
flag = 0;
break;
}
if(flag == 0)break;
}
if(!flag)
printf("Sorry\n");
else
printf("OK\n");
}
return 0;
}