class A:
    def __init__(self, txt: str):
        self.z: H = None
        self.y: F = None
        self.o: E = None
        self.p: G = None
        self.q: H = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: E = None
        self.p: I = None
        self.v: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.z: H = None
        self.v: A = None
        self.o: C = None
        self.t: I = None
        self.w: A = None
        self.u: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: C = None
        self.q: G = None
        self.s: C = None
        self.p: F = None
        self.z: H = None
        self.v: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: H = None
        self.u: H = None
        self.w: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: C = None
        self.q: F = None
        self.r: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.u: C = None
        self.t: I = None
        self.o: A = None
        self.v: A = None
        self.x: C = None
        self.z: G = None
        self.r: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: D = None
        self.y: F = None
        self.z: F = None
        self.s: D = None
        self.r: H = None
        self.v: A = None
        self.u: H = None
        self.txt = txt

c = A("c")
b = B("b")
j = C("j")
d = D("d")
n = E("n")
k = F("k")
g = G("g")
a = H("a")
i = I("i")

c.z = a
c.q = a
c.y = k
c.u = k
c.o = n
c.p = g
b.s = n
b.v = n
b.p = i
j.z = d
d.s = i
d.t = i
d.z = a
d.v = c
d.w = c
d.o = j
d.u = j
n.u = j
n.s = j
n.q = g
n.p = k
n.z = a
n.v = i
k.q = a
k.u = a
k.w = n
g.p = j
g.q = k
g.r = n
a.s = g
a.z = g
a.u = j
a.x = j
a.r = j
a.t = i
a.o = c
a.v = c
i.x = d
i.s = d
i.y = k
i.z = k
i.r = a
i.u = a
i.v = c
assert a.t.v.y.u.txt == "
class A:
    def __init__(self, txt: str):
        self.z: H = None
        self.y: F = None
        self.o: E = None
        self.p: G = None
        self.q: H = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: E = None
        self.p: I = None
        self.v: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.z: H = None
        self.v: A = None
        self.o: C = None
        self.t: I = None
        self.w: A = None
        self.u: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: C = None
        self.q: G = None
        self.s: C = None
        self.p: F = None
        self.z: H = None
        self.v: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: H = None
        self.u: H = None
        self.w: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: C = None
        self.q: F = None
        self.r: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.u: C = None
        self.t: I = None
        self.o: A = None
        self.v: A = None
        self.x: C = None
        self.z: G = None
        self.r: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: D = None
        self.y: F = None
        self.z: F = None
        self.s: D = None
        self.r: H = None
        self.v: A = None
        self.u: H = None
        self.txt = txt

c = A("c")
b = B("b")
j = C("j")
d = D("d")
n = E("n")
k = F("k")
g = G("g")
a = H("a")
i = I("i")

c.z = a
c.q = a
c.y = k
c.u = k
c.o = n
c.p = g
b.s = n
b.v = n
b.p = i
j.z = d
d.s = i
d.t = i
d.z = a
d.v = c
d.w = c
d.o = j
d.u = j
n.u = j
n.s = j
n.q = g
n.p = k
n.z = a
n.v = i
k.q = a
k.u = a
k.w = n
g.p = j
g.q = k
g.r = n
a.s = g
a.z = g
a.u = j
a.x = j
a.r = j
a.t = i
a.o = c
a.v = c
i.x = d
i.s = d
i.y = k
i.z = k
i.r = a
i.u = a
i.v = c
assert a.t.v.y.u.txt == "a"