#include<math.h>
double r[4],d[4][2]={2,2,2,-2,-2,2,-2,-2};
void high(double x,double y)
{
int i;
for(i=0;i<4;i++)
r[i]=sqrt((x-d[i][0])*(x-d[i][0])+(y-d[i][1])*(x-d[i][1]));
}
int main()
{
double x,y;
int i,flag;
while(scanf("%lf%lf",&x,&y))
{
high(x,y);
flag=0;
for(i=0;i<4;i++)
{
if(r[i]<=1)
{
printf("%lf\n",50.0-50.0*r[i]/0.5);
flag=1;
}
}
if(flag==0)
printf("0\n");
}
return 0;
}