int?main(void)
{
int?x,y,i,j,k,sum,t;
while(scanf("%d%d",&x,&y)!=EOF)
{
sum=0;
if(x==0&&y==0)?break;
for(i=x;i<=y;i++)
{
t=i*i+i+41;
k=1;
for(j=2;j*j<=t;j++)
{
if(t%j==0)
{
k=0;
break;
}
}
if(k)
sum++;
}
if(sum==y-x+1)
printf("OK\n");
else
printf("Sorry\n");
}
return?0;
}