#include <cstdio> #include <cmath> using namespace std; inline double f(double x, int n) { if(n > 1) return sqrt(n + f(x, n - 1)); else return sqrt(1 + x); } int main() { double x; scanf("%lf", &x); int n; scanf("%d", &n); return printf("%.2lf", f(x, n)), 0; }