D
S
o
l
v
e
[
{
(
k
+
k
T
a
n
h
[
(
S
q
r
t
[
k
]
x
)
/
(
2
S
q
r
t
[
D
m
]
)
]
-
k
T
a
n
h
[
(
S
q
r
t
[
k
]
x
)
/
(
2
S
q
r
t
[
D
m
]
)
]
^
2
)
*
(
W
1
[
x
]
-
2
*
W
2
[
x
]
/
R
0
)
+
D
m
*
D
[
W
1
[
x
]
,
{
x
,
2
}
]
0
,
(
D
c
*
k
*
R
0
/
(
4
*
D
m
)
)
*
(
(
1
+
T
a
n
h
[
(
S
q
r
t
[
k
]
x
)
/
(
2
S
q
r
t
[
D
m
]
)
]
)
^
2
)
*
(
W
1
[
x
]
-
2
*
W
2
[
x
]
/
R
0
)
+
D
c
*
D
[
W
2
[
x
]
,
{
x
,
2
}
]
0
}
,
{
W
1
[
x
]
,
W
2
[
x
]
}
,
x
]