def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    N = int(data[0])
    p = float(data[1])
    q = float(data[2])
    
    if q == 0:
        print("{0:.10f}".format(p))
        return
    
    # Initialize a and b arrays
    a = [0.0] * (N + 2)
    b = [0.0] * (N + 2)
    a[0] = 0.0
    b[0] = 1.0
    a[1] = 1.0
    b[1] = 0.0
    
    for i in range(1, N + 1):
        a_next = (a[i] - p * a[i-1]) / q
        b_next = (b[i] - p * b[i-1]) / q
        a[i+1] = a_next
        b[i+1] = b_next
    
    denominator = a[N+1]
    if abs(denominator) < 1e-12:
        f1 = 0.0
    else:
        f1 = -b[N+1] / denominator
    
    # Ensure the output meets the precision requirements
    print("{0:.10f}".format(f1))

if __name__ == "__main__":
    main()