#include#includeint main() { double sum, n; // 把 n 弄成 double int m, i; while (scanf("%lf %d", &n, &m) != EOF) { sum = (double)n; for (i = 0; i < m - 1; i++) { sum += sqrt(1.0 * n); n = sqrt(1.0 * n); } printf("%.2lf\n", sum); }}