#include <iostream>
#include <vector>
#include <cmath>
using namespace std;

int main()
{
    double val = 0;
    vector<double> v;
    char ch = 0;

    while (cin >> val)
    {
        v.push_back(val);
    }
    for (int i = 0; i < v.size(); i++)
    {
        cout << sqrt(v[i]) << endl;
    }
}

OK. Read this carefully: "For each number Ai from the LAST one till the FIRST one..."

Second for loop cout from last element of the vector to first