class A:
    def __init__(self, txt: str):
        self.u: E = None
        self.s: B = None
        self.z: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.r: A = None
        self.q: A = None
        self.x: E = None
        self.o: D = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.r: A = None
        self.q: A = None
        self.x: E = None
        self.o: D = None
        self.txt = txt

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

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

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

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