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

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

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

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

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

k = A("k")
l = B("l")
e = C("e")
h = D("h")
b = E("b")
c = C("c")
i = B("i")
j = E("j")
g = B("g")
n = D("n")

k.z = l
l.s = b
l.y = e
l.t = j
e.y = j
e.v = b
e.q = c
e.s = c
h.u = i
h.t = k
h.o = b
h.q = e
b.y = c
b.w = i
c.y = b
c.v = b
c.q = e
c.s = e
i.s = j
i.t = j
i.y = e
j.y = c
j.w = i
g.s = b
g.y = e
g.t = j
n.u = l
n.t = k
n.o = b
n.q = c
assert i.y.y.y.v.y.v.w.y.s.txt == "
class A:
    def __init__(self, txt: str):
        self.z: B = None
        self.txt = txt

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

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

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

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

k = A("k")
l = B("l")
e = C("e")
h = D("h")
b = E("b")
c = C("c")
i = B("i")
j = E("j")
g = B("g")
n = D("n")

k.z = l
l.s = b
l.y = e
l.t = j
e.y = j
e.v = b
e.q = c
e.s = c
h.u = i
h.t = k
h.o = b
h.q = e
b.y = c
b.w = i
c.y = b
c.v = b
c.q = e
c.s = e
i.s = j
i.t = j
i.y = e
j.y = c
j.w = i
g.s = b
g.y = e
g.t = j
n.u = l
n.t = k
n.o = b
n.q = c
assert i.y.y.y.v.y.v.w.y.s.txt == "c"