import sys

def main():
    X, K = map(int, sys.stdin.readline().split())
    
    if X == 1:
        result = (0.75) ** K
        print("{0:.10f}".format(result))
    else:
        if K == 1:
            print("0.5000000000")
        else:
            s = 0.0
            n = 2
            while True:
                term = 1.0 / (n ** K)
                if term < 1e-13:
                    break
                s += term
                n += 1
            print("{0:.10f}".format(s))
    
if __name__ == "__main__":
    main()