text: #include <cmath>
  #include <cstdio>
  using namespace std;
  
  const double eps = 1e-12;
  
  double l, r, lmid, rmid, a, b;
  
  inline double f(double x)
  {
  	return cosh(x) + x;
  }
  
  int main()
  {
  	scanf("%lf %lf", &l, &r);
  	while (r - l > eps)
  	{
  		lmid = (l + r) / 2.0;
  		rmid = (lmid + r) / 2.0;
  		if (f(lmid) < f(rmid)) r = rmid;
  		else l = lmid;
  	}
  	printf("%.4lf\n", f(l));
  	return 0;
  }