import math

def compute_zeta_minus_1(K):
    if K == 1:
        return 0.5
    s = 0.0
    n = 2
    while True:
        term = 1.0 / (n ** K)
        if term < 1e-15:  # Term is negligible for the required precision
            break
        s += term
        n += 1
    return s

X, K = map(int, input().split())

if X == 1:
    result = (0.75) ** K
    print("{0:.10f}".format(result))
elif X == 2:
    if K == 1:
        print("0.5000000000")
    else:
        res = compute_zeta_minus_1(K)
        print("{0:.10f}".format(res))