class A:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: C = None
        self.v: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: H = None
        self.o: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: F = None
        self.u: F = None
        self.s: C = None
        self.q: E = None
        self.r: D = None
        self.z: C = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: H = None
        self.o: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: F = None
        self.u: F = None
        self.s: C = None
        self.q: E = None
        self.r: D = None
        self.z: C = None
        self.txt = txt

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

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