class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.r: F = None
        self.q: D = None
        self.z: H = None
        self.v: H = None
        self.w: D = None
        self.s: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: C = None
        self.s: I = None
        self.w: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: D = None
        self.o: G = None
        self.v: G = None
        self.r: G = None
        self.p: E = None
        self.q: G = None
        self.u: D = None
        self.s: C = None
        self.x: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: H = None
        self.z: C = None
        self.p: E = None
        self.x: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: I = None
        self.o: B = None
        self.z: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: G = None
        self.p: E = None
        self.r: H = None
        self.txt = txt

k = A("k")
b = B("b")
n = C("n")
l = D("l")
m = E("m")
e = F("e")
c = G("c")
f = H("f")
a = I("a")
j = F("j")

k.u = n
k.r = j
k.q = l
k.w = l
k.z = f
k.v = f
k.s = b
b.x = c
b.s = m
b.v = a
b.q = k
b.p = n
b.z = f
b.u = f
n.x = c
l.r = b
l.u = n
l.s = a
l.w = k
m.p = n
e.w = l
e.u = l
e.o = c
e.v = c
e.r = c
e.q = c
e.p = m
e.x = m
e.s = n
c.v = f
c.z = n
c.x = n
c.p = m
f.r = a
f.z = a
f.o = b
a.z = c
a.p = m
a.r = f
j.w = l
j.u = l
j.o = c
j.v = c
j.r = c
j.q = c
j.p = m
j.x = m
j.s = n
assert c.x.x.x.txt == "
class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.r: F = None
        self.q: D = None
        self.z: H = None
        self.v: H = None
        self.w: D = None
        self.s: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: C = None
        self.s: I = None
        self.w: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: D = None
        self.o: G = None
        self.v: G = None
        self.r: G = None
        self.p: E = None
        self.q: G = None
        self.u: D = None
        self.s: C = None
        self.x: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: H = None
        self.z: C = None
        self.p: E = None
        self.x: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: I = None
        self.o: B = None
        self.z: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: G = None
        self.p: E = None
        self.r: H = None
        self.txt = txt

k = A("k")
b = B("b")
n = C("n")
l = D("l")
m = E("m")
e = F("e")
c = G("c")
f = H("f")
a = I("a")
j = F("j")

k.u = n
k.r = j
k.q = l
k.w = l
k.z = f
k.v = f
k.s = b
b.x = c
b.s = m
b.v = a
b.q = k
b.p = n
b.z = f
b.u = f
n.x = c
l.r = b
l.u = n
l.s = a
l.w = k
m.p = n
e.w = l
e.u = l
e.o = c
e.v = c
e.r = c
e.q = c
e.p = m
e.x = m
e.s = n
c.v = f
c.z = n
c.x = n
c.p = m
f.r = a
f.z = a
f.o = b
a.z = c
a.p = m
a.r = f
j.w = l
j.u = l
j.o = c
j.v = c
j.r = c
j.q = c
j.p = m
j.x = m
j.s = n
assert c.x.x.x.txt == "n"