struct Point {
    float x;
    float y;
    float z;

    Point operator - (const Point& other) const {
        return { x - other.x, y - other.y, z - other.z };
    }
};

struct Eq {
    float a;
    float b;
    float c;
    float d;

    Eq() {}

    Eq(float a, float b, float c, float d) : a(a), b(b), c(c), d(d) {}

    Eq(const Point& A, const Point& B, const Point& C) {
        Point v1 = B - A;
        Point v2 = C - A;

        Point norm = { v1.y * v2.z - v1.z * v2.y, v1.z * v2.x - v1.x * v2.z, v1.x * v2.y - v1.y * v2.x };

        a = norm.x;
        b = norm.y;
        c = norm.z;
        d = -(norm.x * A.x + norm.y * A.y + norm.z * A.z);
    }

    float operator () (const Point& p) {
        float ans = (a * p.x + b * p.y + c * p.z + d) / sqrt(a * a + b * b + c * c);
        return ans;
    }
};