#include<bits/stdc++.h>
using namespace std;
int n,m;
int xw[1007],sz[1007];
bool zs(int a){
if(a==0||a==1) return false;
if(a==2) return true;
for(int i=2;i*i<=a;i++){
if(a%i==0) return false;
}
return true;
}
void work(int a,int b){
long long ans=0;
for(int j=a;j<=b;j++){
if(zs(j)) ans++;
}
cout<<ans<<endl;
}
int main(){
cin>>n>>m;
for(int i=0;i<n;i++){
cin>>xw[i]>>sz[i];
if(xw[i]<1||sz[i]>m){
cout<<"Crossing the line"<<endl;
continue;
}
work(xw[i],sz[i]);
}
}
实在不行,81分,4-6TLE,求大佬帮忙