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

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.o: E = None
        self.z: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: C = None
        self.q: E = None
        self.r: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.u: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.y: C = None
        self.v: D = None
        self.t: D = None
        self.r: B = None
        self.txt = txt

i = A("i")
l = B("l")
b = C("b")
a = D("a")
c = E("c")
j = C("j")
g = A("g")
f = A("f")

i.p = a
i.s = c
i.v = b
l.y = c
l.o = c
l.z = b
b.s = j
b.q = c
b.r = a
a.v = l
a.u = j
c.o = j
c.y = b
c.v = a
c.t = a
c.r = l
j.s = b
j.q = c
j.r = a
g.p = a
g.s = c
g.v = j
f.p = a
f.s = c
f.v = b
assert b.s.q.y.s.s.r.u.txt == "
class A:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: E = None
        self.v: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.o: E = None
        self.z: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: C = None
        self.q: E = None
        self.r: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.u: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.y: C = None
        self.v: D = None
        self.t: D = None
        self.r: B = None
        self.txt = txt

i = A("i")
l = B("l")
b = C("b")
a = D("a")
c = E("c")
j = C("j")
g = A("g")
f = A("f")

i.p = a
i.s = c
i.v = b
l.y = c
l.o = c
l.z = b
b.s = j
b.q = c
b.r = a
a.v = l
a.u = j
c.o = j
c.y = b
c.v = a
c.t = a
c.r = l
j.s = b
j.q = c
j.r = a
g.p = a
g.s = c
g.v = j
f.p = a
f.s = c
f.v = b
assert b.s.q.y.s.s.r.u.txt == "j"