记录

#include<iostream>
using namespace std;
int l,r,n,m;
bool ss[1000000];
int main()
{
    ss[1] = true;
    cin >> n >> m;
    for (int i = 2; i <= m;i++)
    {
        if (!ss[i])
        {
            for (int j = 2; j * i <= m;j++)
            {
                ss[i * j] = true;
            }
        }
    }
    for (int i = 1; i <= n;i++)
    {
        cin >> l >> r;
        if(l<1 || r>m)
        {
            cout<<"Crossing the line"<<endl;
        }
        else
        {
            int ans = 0;
            for (int j = l; j <= r;j++)
            {
                if(!ss[j])
                    ans++;
            }
            cout<<ans<<endl;
        }
    }
    return 0;
}