#include <stdio.h>
#include <math.h>

int main() {
    double a, b, c;
    double x1, x2;
    printf("Input a, b, c:\n");
    scanf("%lf%lf%lf", &a, &b, &c);
    double d = b*b - 4.*a*c;
    if (d < 0.) {
        printf("No roots.\n");
    } else {
        d = sqrt(d);
        x1 = (-b + d) / (2.*a);
        x2 = (-b - d) / (2.*a);
        printf("x1=%f, x2=%f\n", x1, x2);
    }
    return 0;
}