I tried everything:
1. Reading long long and then casting as needed to long double
2. Reading and doing operations with long double
3. Searching root with binary search

#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
#include <climits>

using namespace std;

int main()
{
    long double a;
    vector<long double> v;
    while (scanf("%lf", &a) != EOF) {
        v.push_back(a);
    }
    reverse(v.begin(), v.end());

    for (vector<long double>::iterator it = v.begin(); it != v.end(); ++it) {
        printf("%.4lf\n", sqrt(*it));
    }
    return 0;
}