ht01-4

#include <stdio.h>

int
main(void)
{
    enum
    {
        COEFFICIENT1 = 4,
        TWO_ANSWER = 2
    };
    int a, b, c, ans = 0;
    long long d;
    double x1, x2, sqrt_d;

    scanf("%d%d%d", &a, &b, &c);
    if(a && b && c)
    {
        d = b * 1LL * b - COEFFICIENT1 * 1LL * a * c;
        if (d == 0) {
            ans = 1;
            x1 = (double) -b / (2 * a);
        } else if (d > 0) {
            ans = TWO_ANSWER;
            sqrt_d = sqrt(d);
            x1 = (-b - sqrt_d) / (2 * a);
            x2 = (-b + sqrt_d) / (2 * a);
        }
    } else if (a && b) {
        ans = TWO_ANSWER;
        if(b < 0) {
            x1 = 0;
            x2 = (double) -b / a;
        } else {
            x1 = (double) -b / a;
            x2 = 0;
        }
    } else if (a && c) {
        if(-c * 1LL * a > 0) {
            ans = TWO_ANSWER;
            x1 = -sqrt((double) -c / a);
            x2 = -x1;
        }
    } else if (a) {
        ans = 1;
        x1 = 0;
    } else if (b && c) {
        ans = 1;
        x1 = (double) -b / c;
    } else if (b) {
        ans = 1;
        x1 = 0;
    } else if (c == 0) {
        ans = -1;
    }


    printf("%d", ans);
    if(ans > 0) {
        printf(" %.10lf", x1);
    }
    if(ans > 1) {
        printf(" %.10lf", x2);
    }
    printf("\n");
    return 0;
}