程序无法运行出结果

#include<stdio.h>
 #include<math.h>
 int main()
 {
double a,b,c,disc,x1,x2,realpart,imagpart;
scanf("%lf,%lf,%lf\n",&a,&b,&c);
printf("The equation");
if (fabs(a)<1e-6)
 printf("is not a quadratic\n");
else
{
disc=b*b-4*a*c;
if (fabs(disc)<=1e-6)
{
 x1=-b/(2*a);
 printf("This equation has two equal roots=%8.4f\n",x1); 
}
 else
if (fabs(disc)>1e-6)
{
 x1=(-b+sqrt(disc))/(2*a);
 x2=(-b-sqrt(disc))/(2*a);
 printf("This equation has twp disctinc roots=%8.4f,%8.4f",x1,x2);
}
 else
{
 realpart=-b/(2*a);
 imagpart=sqrt(disc)/(2*a);
 printf("x1=%8.4f+%8.4fi",realpart,imagpart);
 printf("x1=%8.4f-%8.4fi",realpart,imagpart);
 }
}
return 0;
 }