def main():
    import sys
    input = sys.stdin.read().split()
    N = int(input[0])
    p = float(input[1])
    q = float(input[2])

    if N == 0:
        print(1.0)
        return

    # Handle special cases where division by zero might occur
    if 1 - p == 0:
        if q == 0:
            print(1.0)
            return
        else:
            print(0.0)
            return

    # Compute c_i using the recurrence
    c = [0.0] * (N + 1)
    c[0] = q / (1 - p)
    c[1] = 1.0

    for i in range(2, N + 1):
        if q == 0:
            if c[i-1] - p * c[i-2] == 0:
                c[i] = 0.0
            else:
                c[i] = float('inf')  # Handle division by zero
        else:
            c[i] = (c[i-1] - p * c[i-2]) / q

    # Check if c_N == p * c_{N-1}
    if abs(c[N] - p * c[N-1]) < 1e-10:
        f1 = 1.0  # Arbitrary since condition holds
    else:
        # Compute the required factor to satisfy the condition
        numerator = p * c[N-2] - (1 - p * q) * c[N-1]
        denominator = (1 - p * q) * c[N-1] - p * c[N-2]
        if denominator == 0:
            f1 = 0.0
        else:
            f1 = numerator / denominator

    # Compute f0
    f0 = q * f1 / (1 - p)
    print("{0:.12f}".format(f0))

if __name__ == "__main__":
    main()