XCOJ 1008: 级数求和

#include <iostream>
#include<math.h>
#include <iomanip>
#include<cstdio>
#include<string>
#include<map>
#include<vector>
#include<list>
#include<algorithm>
#include<stdlib.h>
#include<iterator>
#include<sstream>
#include<string.h>
#include<stdio.h>
using namespace std;

int main()
{
    double a;
    int k;
    while(cin>>k)
    {
        double sum=1;
        a=1;

        while(sum<=k)
        {
            sum=sum+1.0/(a+1);
            a++;
        }
        cout<<a<<endl;
    }

    return 0;
}