How many triangles are formed when a line segment is drawn from one vertex of a nonagon to a non-neighboring vertex?
9 3 [OP_SUB] 1 [OP_ADD]
var_a = 9
var_b = 3
var_c = var_a - var_b
var_d = 1
var_e = var_c + var_d
print(int(var_e))