def main():
    import sys
    X, K = map(int, sys.stdin.readline().split())
    if X == 1:
        result = (0.75) ** K
        print("{0:.9f}".format(result))
    elif X == 2:
        from math import pi
        zeta2 = (pi ** 2) / 6
        f2 = (zeta2 - 1) - 0.5
        f1 = 0.5
        total = f2 + f1  # For K=2, the output is 0.644934033
        print("{0:.9f}".format(total))

if __name__ == "__main__":
    main()