RT，上代码

#include <bits/stdc++.h>
using namespace std;
int sum=0,num=0,L;
int main()
{
    cin>>L;
    for (int i=2;;i++)
    {
        int prime = 1;
        for (int j=2;j*j<=i;j++)
        {
            if (i%j==0)
            {
                prime = 0;
                break;
            }
        }
        if (prime !=0) continue;
        if (num+i>L) break;
        cout <<i<<endl;
        num+=i;
        sum++;
    }
    cout <<sum;
    return 0;
}

搞了好久