H

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

using namespace std;

const long double inf = 2e18;

struct point {
    long double x, y;

    long double len() {
        return sqrt(x * x + y * y);
    }

    void build(long double a, long double b) {
        x = a;
        y = b;
    }
};

struct line {
    long double a, b, c, k, m;

    long double getY(long double x) {
        if (b == 0) {
            return inf;
        }

        return -(c + a * x) / b;
    }

    long double getX(long double y) {
        if (a == 0) {
            return inf;
        }

        return -(c + b * y) / a;
    }

    void buildPoints(point x, point y) {
        a = x.y - y.y;
        b = y.x - x.x;
        c = x.x * y.y - y.x * x.y;

        if (b == 0) {
            m = inf + x.x;
            k = inf;
        } else {
            m = -c / b;
            k = -a / b;
        }
    }

    void build(long double A, long double B, long double C) {
        a = A;
        b = B;
        c = C;

        if (b == 0) {
            m = inf;
            k = inf;
        } else {
            m = -c / b;
            k = -a / b;
        }
    }

    long double distance(point p) {
        return abs(a * p.x + b * p.y + c) / sqrt(a * a + b * b);
    }
};

struct circle {
    point center;
    long double radius;

    pair<long double, long double> getY(long double x) {
        pair<long double, long double> res = {inf, inf};
        long double a = 1, b, c, d;
        b = -2 * center.y;
        c = center.y * center.y - radius * radius + (x - center.x) * (x - center.x);
        d = b * b - 4.0 * a * c;

        if (d == 0) {
            res.first = -b / 2.0;
        }

        if (d > 0) {
            res.first = (-b + sqrt(d)) / 2.0 / a;
            res.first = (-b - sqrt(d)) / 2.0 / a;
        }

        return res;
    }
};

point operator*(long double k, point a) {
    point res;
    res.x = a.x * k;
    res.y = a.y * k;
    return res;
}

long double operator*(point a, point b) {
    return a.x * b.x + a.y * b.y;
}

long double operator^(point a, point b) {
    return a.x * b.y - a.y * b.x;
}

point operator-(point a, point b) {
    point res;

    res.x = a.x - b.x;
    res.y = a.y - b.y;

    return res;
}

point operator+(point a, point b) {
    point res;

    res.x = a.x + b.x;
    res.y = a.y + b.y;

    return res;
}

int main() {

    circle o;
    line l;
    point ans1, ans2, p;
    long double x, y, z, D, a, b, c, d;

    scanf("%Lf %Lf %Lf %Lf %Lf %Lf", &o.center.x, &o.center.y, &o.radius, &x, &y, &z);

    l.build(x, y, z);

    a = l.a * l.a + l.b * l.b;
    b = 2.0 * (l.a * l.c - o.center.x * l.b * l.b + l.a * l.b * o.center.y);
    c = o.center.x * o.center.x * l.b * l.b + l.c * l.c + 2 * l.c * l.b * o.center.y + o.center.y * o.center.y * l.b * l.b - l.b * l.b * o.radius * o.radius;
    d = b * b - 4.0 * a * c;

    if (l.distance(o.center) > o.radius) {
        printf("0");
    } else {
        if (l.distance(o.center) == o.radius) {
            ans1.x = -b / 2.0 / a;

            if (!l.b) {
                ans1.y = o.getY(ans1.x).first;
            } else {
                ans1.y = l.getY(ans1.x);
            }

            printf("1\n");
            printf("%Lf %Lf", ans1.x, ans1.y);
        } else {
            ans1.x = (-b + sqrt(d)) / 2.0 / a;
            ans2.x = (-b - sqrt(d)) / 2.0 / a;

            if (!l.b) {
                ans1.y = o.getY(ans1.x).first;
                ans2.y = o.getY(ans1.x).second;
            } else {
                ans1.y = l.getY(ans1.x);
                ans2.y = l.getY(ans2.x);
            }

            printf("2\n");
            printf("%Lf %Lf\n", ans1.x, ans1.y);
            printf("%Lf %Lf\n", ans2.x, ans2.y);
        }
    }

    return 0;
}