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

class B:
    def __init__(self, txt: str):
        self.w: H = None
        self.z: H = None
        self.u: H = None
        self.p: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: A = None
        self.w: F = None
        self.t: C = None
        self.y: B = None
        self.r: C = None
        self.v: A = None
        self.o: A = None
        self.s: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.q: F = None
        self.o: E = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: H = None
        self.z: H = None
        self.u: H = None
        self.p: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: A = None
        self.w: F = None
        self.t: C = None
        self.y: B = None
        self.r: C = None
        self.v: A = None
        self.o: A = None
        self.s: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.q: F = None
        self.o: E = None
        self.txt = txt

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

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

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