参考答案：

#include<iostream>
using namespace std;
int main()
{
    int k;
    cin >> k;
    double i = 1, s = 0, sum = 0;
    while (s <= k)
    {
        s += 1 / i;
        ++i;
        ++sum;
    }
    cout << sum << endl;

    return 0;
}