Z - 5 = U - 4 = Q - 3 = N - 2 = L

1st letter : D + 12 = P + 12 = B + 12 = N
2nd letter : H + 12 = T + 12 = F + 12 = R
3rd letter : L + 12 = X + 12 = J + 12 = V

1st letter : D + 3 = G + 4 = K + 3 = N + 4 = R + 3 = U
2nd letter : F + 4 = J + 3 = M + 4 = Q + 3 = T + 4 = X

A + 3 = D + 4 = H + 5 = M + 6 = S + 7 = Z

1st letter : A + 1 = B + 1 = C + 1 = D + 1 = E
2nd letter : Z - 5 = U + (5 - 2) = + 3 = X - (3 - 2) = - 1 = W + (1 - 2) = - 1 = V
3rd letter : Y - 5 = T + (5 - 2) = + 3 = W - (3 - 2) = - 1 = V + (1 - 2) = - 1 = U

T - 2 = R - 2 = P - 2 = N - 2 = L - 2 = J - 2 = H

Z - 3 = W - 4 = S - 3 = P - 4 = L - 3 = I - 4 = E - 3 = B

U + 7 B + 7 I + 7 P + 7 W + 7 D

A + 6 = G + 5 = L + 4 = P + 3 = S + 2 = U

1st letter : P - 1 = O - 1 = N - 1 = M - 1 = L
2nd letter : M + 2 = O + 2 = Q + 2 = S + 2 = U
3rd letter : T - 1 = S - 1 = R - 1 = Q - 1 = P

1st letter : B + 2 = D + 2 = F + 2 = H
2nd letter : M + 1 = N + 1 = O + 1 = P
3rd letter : X - 1 = W - 2 = U - 1 = T

1st letter : A + 3 = D + 4 = H + 5 = M + 6 = S + 7 = Z
2nd letter : B + 5 = G + 6 = M + 7 = T + 8 = B + 9 = K
3rd letter : D + 7 = K + 8 = S + 9 = B + 10 = L + 11 = W

1st letter : a + 6 = g + 6 = m + 6 = s + 6 = y
2nd letter : j + 6 = p + 6 = v + 6 = b + 6 = h
3rd letter : s + 6 = y + 6 = e + 6 = k + 6 = q

1st letter : W - 3 = T - 3 = Q - 3 = N
2nd letter : F + 1 = G + 1 = H + 1 = I
3rd letter : B + 2 = D + 3 = G + 4 = K

Y - 2 = W - 3 = T - 4 = P - 5 = K - 6 = E - 7 = X - 8 = P - 9 = G

H + 1 = I + 2 = K + 3 = N + 4 = R

(Z→Y→X) - 3 (U→T→S) - 3 (P→O→N) - 3 (K→J→I)

Z - 2 = X - 5 = S - 10 = I - 17 = R - 26 = R - 37 = G - 50 = I

The series may be divided into groups as shown:
b e d / f ? h / j ? l
Clearly in the first group, the second group and third group , letters are respectively three and two steps ahead of the first letter. A similar pattern would follow in the second and third groups.

a + 3 = d - 1 = c + 3 = f - 1 = e + 3 = h - 1 = g + 3 = j - 1 = i