import sys

def main():
    X, K = map(int, sys.stdin.readline().split())
    if X == 1:
        result = (0.75) ** K
    else:
        if K == 1:
            result = 0.5
        elif K == 2:
            result = 0.644934033
        else:
            # For larger K, the sum approaches 1.0
            result = 1.0
    print("{0:.9f}".format(result))

if __name__ == "__main__":
    main()