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

class B:
    def __init__(self, txt: str):
        self.y: A = None
        self.q: F = None
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: F = None
        self.o: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: F = None
        self.t: F = None
        self.y: H = None
        self.r: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.z: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.o: B = None
        self.q: C = None
        self.t: C = None
        self.p: H = None
        self.z: A = None
        self.v: F = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: D = None
        self.q: B = None
        self.r: D = None
        self.txt = txt

i = A("i")
h = B("h")
l = C("l")
k = D("k")
g = E("g")
m = F("m")
e = G("e")
b = H("b")
c = B("c")
d = G("d")

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

class B:
    def __init__(self, txt: str):
        self.y: A = None
        self.q: F = None
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: F = None
        self.o: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: F = None
        self.t: F = None
        self.y: H = None
        self.r: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.z: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.o: B = None
        self.q: C = None
        self.t: C = None
        self.p: H = None
        self.z: A = None
        self.v: F = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: D = None
        self.q: B = None
        self.r: D = None
        self.txt = txt

i = A("i")
h = B("h")
l = C("l")
k = D("k")
g = E("g")
m = F("m")
e = G("e")
b = H("b")
c = B("c")
d = G("d")

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