def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    idx = 0
    n = int(data[idx])
    idx += 1
    H = int(data[idx])
    idx += 1
    points = []
    for _ in range(n):
        x = int(data[idx])
        y = int(data[idx + 1])
        points.append((x, y))
        idx += 2

    a1 = 0.0
    a2 = 0.0
    epsilon = 1e-8
    max_iter = 10000
    for _ in range(max_iter):
        Sf = []
        Sg = []
        for x, y in points:
            err_f = (y - a1 * x - H) ** 2
            err_g = (y - a2 * x) ** 2
            if err_f <= err_g:
                Sf.append((x, y))
            else:
                Sg.append((x, y))
        
        sum_xy_f = 0.0
        sum_x2_f = 0.0
        for x, y in Sf:
            sum_xy_f += x * (y - H)
            sum_x2_f += x * x
        if sum_x2_f != 0:
            a1_new = sum_xy_f / sum_x2_f
        else:
            a1_new = a1
        
        sum_xy_g = 0.0
        sum_x2_g = 0.0
        for x, y in Sg:
            sum_xy_g += x * y
            sum_x2_g += x * x
        if sum_x2_g != 0:
            a2_new = sum_xy_g / sum_x2_g
        else:
            a2_new = a2
        
        if abs(a1_new - a1) < epsilon and abs(a2_new - a2) < epsilon:
            a1 = a1_new
            a2 = a2_new
            break
        a1 = a1_new
        a2 = a2_new
    
    total = 0.0
    for x, y in points:
        err_f = (y - a1 * x - H) ** 2
        err_g = (y - a2 * x) ** 2
        total += min(err_f, err_g)
    print("{0:.15f}".format(total))

if __name__ == "__main__":
    main()