#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <iomanip>
#include <sys/time.h>
#include <random>
using namespace std;

#define endl '\n'
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef long double ld;
typedef pair<int, int> P;
typedef complex<double> comp;
typedef vector< vector<ld> > matrix;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};
const int inf = 1e9 + 9;
const ll mod = 1e9 + 7;
const double eps = 1e-8;
const double pi = acos(-1);

int n;
ld p[3];
ld q[300][3];

ld norm(ld a, ld b, ld c) {
    return sqrt(a*a+b*b+c*c);
}

ld dist(int i, int j, int k) {
    ld r[2][3];
    for (int l = 0; l < 3; l++) {
        r[0][l] = q[j][l] - q[i][l];
        r[1][l] = q[k][l] - q[i][l];
    }
    ld c[3];
    for (int l = 0; l < 3; l++) {
        c[l] = r[0][(l+1)%3] * r[1][(l+2)%3] - r[0][(l+2)%3] * r[1][(l+1)%3];
    }
    ld d = 0.0;
    for (int l = 0; l < 3; l++) {
        d += c[l] * q[i][l];
    }
    d *= -1;
    ld res = d;
    for (int l = 0; l < 3; l++) {
        res += p[l] * c[l];
    }
    return abs(res) / norm(c[0], c[1], c[2]);
}

ld solve() {
    ld res = 0.0;
    for (int i = 0; i < n; i++) {
        for (int j = i+1; j < n; j++) {
            for (int k = j+1; k < n; k++) {
                res += dist(i, j, k);
            }
        }
    }
    return res;
}

void input() {
    cin >> n;
    cin >> p[0] >> p[1] >> p[2];
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < 3; j++) cin >> q[i][j];
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);

    input();
    cout << solve() << endl;
}