#include "stdio.h"
#include "math.h"
#define PI 3.14159265358979
int main()
{
	double r,h,d1,A1,d2,A2,l,dA;
	dA=0.0;
	l=0.0;
	while(scanf("%lf",&r)!=-1)
	{
		scanf("%lf%lf%lf%lf%lf",&h,&d1,&A1,&d2,&A2);
		dA=fabs(A1-A2);
		if(dA>180.0)dA=360-dA;
		dA=r/sqrt(h*h+r*r)*dA*PI/180.0;
		l=sqrt(d1*d1+d2*d2-2*d1*d2*cos(dA));
		printf("%.2lf\n",l);
	}
}