#include<bits/stdc++.h>
using namespace std;

bool prime(int n){
	if (n == 0 && n == 1){
		return 0;
	}
	for (int i = 2; i <= sqrt(n); i++){
		if (n%i == 0){
			return 0;
		}
	}
	return 1;
}
int main(){
	int n, m;
	int ans;
	cin >> n >> m;
	while(n--){
		ans = 0;
		int a, b;
		cin >> a >> b;
		if (a < 1 || b > m){
			cout << "Crossing the line" << endl;
			continue;
		}
		for (int i = a; i <= b; i++){
			if (prime(i) == 1){
				ans++;
			}
		}
		cout << ans << endl;
	}
}