Марсианские спутники

#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <vector>
#include <stdio.h>
#include <cmath>
#include <math.h>
#include <queue>
#include <stack>
#include <climits>
#include <deque>
#include <ctime>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;

#define mh() make_heap()
#define poph() pop_heap()
#define pushh() push_heap()
#define sor(n) n.begin(), n.end()
#define mp make_pair

ll Round(double k)
{
    if (ll(k*10)%10 < 0.5)
        return int(k) + 1;
    else
        return int(k);
}
int main()
{
    double a, b, e, d;
    cin >> a >> b >> d >> e;
    double answ;
    if (abs(a*b - d*e) < 1e-9)
        cout << "Impossible.";
    else
    {
        answ = sqrt(d*d + e*e - d*e*((a*a + b*b - d*d - e*e) / (a*b - d*e)));
        answ *= 1000;
        printf("Distance is %.0f km.", answ);
    }

    return 0;
}