class A:
    def __init__(self, txt: str):
        self.r: F = None
        self.p: E = None
        self.t: C = None
        self.u: A = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: A = None
        self.w: D = None
        self.s: A = None
        self.u: E = None
        self.x: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: A = None
        self.p: F = None
        self.o: B = None
        self.v: E = None
        self.t: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.w: C = None
        self.z: E = None
        self.q: E = None
        self.txt = txt

n = A("n")
i = B("i")
a = C("a")
l = D("l")
d = E("d")
h = F("h")
j = B("j")
c = F("c")
m = F("m")
b = A("b")

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

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

class C:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: A = None
        self.w: D = None
        self.s: A = None
        self.u: E = None
        self.x: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: A = None
        self.p: F = None
        self.o: B = None
        self.v: E = None
        self.t: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.w: C = None
        self.z: E = None
        self.q: E = None
        self.txt = txt

n = A("n")
i = B("i")
a = C("a")
l = D("l")
d = E("d")
h = F("h")
j = B("j")
c = F("c")
m = F("m")
b = A("b")

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