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

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

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

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

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

l = A("l")
b = B("b")
f = C("f")
k = D("k")
d = E("d")
i = A("i")
j = E("j")
g = A("g")
m = E("m")

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

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

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

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

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

l = A("l")
b = B("b")
f = C("f")
k = D("k")
d = E("d")
i = A("i")
j = E("j")
g = A("g")
m = E("m")

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