#include
int main()
{ int a=2,b=-4,c=1;
float d,x1,x2;
d=b*b-4*a-c;
if(d>=0)
{x1=(-b+sqrt(d))/(2*a);
x2=(-b-sqrt(d))/(2*a);
if(x1>=0&&x1<=1)printf("%f\n",x1);
if(x1-x2&&x2>=0&&x2<=1)printf("%f\n",x2);
}
return 0;