jq, 97 bytes

Result

AC

Duration

625ms

Code [DL]

scan("[a-z][0-9]*")|if ((.|length)==2) then (.[0:1] as $c|(range(.[1:2]|tonumber)|$c)) else . end

stdin

z4v2o4u7ufkjx2l8eb6t8r8g4e6w8l6g9v3o5d9y9q9u3j6m4p9f6g4i7s4cm8u2w3x5t8n6w5s2a7d6p7i9h9j3z5v2f7

stdout

z
z
z
z
v
v
o
o
o
o
u
u
u
u
u
u
u
u
f
k
j
x
x
l
l
l
l
l
l
l
l
e
b
b
b
b
b
b
t
t
t
t
t
t
t
t
r
r
r
r
r
r
r
r
g
g
g
g
e
e
e
e
e
e
w
w
w
w
w
w
w
w
l
l
l
l
l
l
g
g
g
g
g
g
g
g
g
v
v
v
o
o
o
o
o
d
d
d
d
d
d
d
d
d
y
y
y
y
y
y
y
y
y
q
q
q
q
q
q
q
q
q
u
u
u
j
j
j
j
j
j
m
m
m
m
p
p
p
p
p
p
p
p
p
f
f
f
f
f
f
g
g
g
g
i
i
i
i
i
i
i
s
s
s
s
c
m
m
m
m
m
m
m
m
u
u
w
w
w
x
x
x
x
x
t
t
t
t
t
t
t
t
n
n
n
n
n
n
w
w
w
w
w
s
s
a
a
a
a
a
a
a
d
d
d
d
d
d
p
p
p
p
p
p
p
i
i
i
i
i
i
i
i
i
h
h
h
h
h
h
h
h
h
j
j
j
z
z
z
z
z
v
v
f
f
f
f
f
f
f

stderr

strace