#include<bits/stdc++.h>
#define maxn 10000000
using namespace std;
bool pi(int x)
{
	if(x==1)	return 1;
	for(int i=2;i*i<=x;i++)
		if(x%i==0)
			return 1;
	return 0;		
}
int shu(int x,int y)
{
	int sum=0;
	for(int i=x;i<=y;i++)
		if(pi(i)==0)
			sum++;
	return sum;
}
int n,m;
int a[maxn],b[maxn];
int main (){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)
	{
		scanf("%d%d",&a[i],&b[i]);
		if(a[i]<1 || b[i]>m || b[i]<1)
			printf("Crossing the line\n");
		else
			printf("%d\n",shu(a[i],b[i]));
	}
	return 0;
}