How many "Heavenly Stems" **** in our country's traditional order?

The Heavenly Stems and Earthly Branches is referred to as the "Stems and Branches",

The Heavenly Stems are ten: A, B, C, D, E, F, G, C, N, N, D;

The Earthly Branches are twelve: Zi, U, C, D, C, S, F, N, W, S, Y, Y, X, X, H, H. The ten stems and twelve branches are matched in order to form the sixty basic units.

Ten stems and twelve branches in order to match, composed of sixty basic units, the ancients as the year, month, day, hour of the serial number, called "stems and branches of the chronicle".