class A:
    def __init__(self, txt: str):
        self.q: D = None
        self.r: F = None
        self.z: B = None
        self.p: C = None
        self.y: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: A = None
        self.x: A = None
        self.p: E = None
        self.o: B = None
        self.w: F = None
        self.y: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.u: E = None
        self.z: E = None
        self.r: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: F = None
        self.u: D = None
        self.q: F = None
        self.o: D = None
        self.r: E = None
        self.v: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: A = None
        self.x: A = None
        self.p: E = None
        self.o: B = None
        self.w: F = None
        self.y: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.u: E = None
        self.z: E = None
        self.r: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: F = None
        self.u: D = None
        self.q: F = None
        self.o: D = None
        self.r: E = None
        self.v: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

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

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