#include <iostream>
#include <math.h>
#include <algorithm>
#include <vector>

using namespace std;

int main()
{
    vector<long long int>v;

    long long int b;

    while (cin >> b) v.push_back(b);

    reverse(v.begin(),v.end());

    for (long long int k: v) cout << fixed << sqrt(k) << "\n";

    return 0;
}

Try sqrt(k + 0.0)