We present results of the multicolour UBVR photometry of the high-amplitude EC 14026-type star , Balloon 090100001 .
The data span over a month and consist of more than a hundred hours of observations .
Fourier analysis of these data led us to the detection of at least 30 modes of pulsation of which 22 are independent .
The frequencies of 13 detected modes group in three narrow ranges , around 2.8 , 3.8 and 4.7 mHz , where the radial fundamental mode , the first and second overtones are likely to occur .
Surprisingly , we also detect 9 independent modes in the low-frequency domain , between 0.15 and 0.4 mHz .
These modes are typical for pulsations found in PG 1716+426-type stars , discovered recently among cool B-type subdwarfs .
The modes found in these stars are attributed to the high-order g modes .
As both kinds of pulsations are observed in Balloon 090100001 , it represents a link between the two classes of pulsating hot subdwarfs .
At present , it is probably the most suitable target for testing evolutionary scenarios and internal constitution models of these stars by means of asteroseismology .

Three of the modes we discovered form an equidistant frequency triplet which can be explained by invoking rotational splitting of an \ell = 1 mode .
The splitting amounts to about 1.58 \mu Hz , leading to a rotation period of 7.1 \pm 0.1 days .