class A:
    def __init__(self, txt: str):
        self.w: C = None
        self.y: F = None
        self.x: F = None
        self.t: E = None
        self.s: H = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.x: G = None
        self.u: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: I = None
        self.q: A = None
        self.t: H = None
        self.v: D = None
        self.p: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: F = None
        self.q: F = None
        self.t: A = None
        self.v: I = None
        self.y: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: D = None
        self.y: D = None
        self.z: G = None
        self.p: C = None
        self.v: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: A = None
        self.t: C = None
        self.o: I = None
        self.q: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: G = None
        self.r: F = None
        self.y: G = None
        self.s: A = None
        self.x: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: D = None
        self.p: A = None
        self.u: H = None
        self.q: C = None
        self.w: E = None
        self.txt = txt

d = A("d")
h = B("h")
n = C("n")
e = D("e")
l = E("l")
a = F("a")
j = G("j")
i = H("i")
b = I("b")

d.w = n
d.y = a
d.x = a
d.u = a
d.t = l
d.s = i
h.v = j
h.x = j
h.u = j
n.o = b
n.q = d
n.t = i
n.v = e
n.p = e
e.w = l
e.r = a
e.q = a
e.t = d
e.v = b
e.y = n
l.u = h
l.r = e
l.y = e
l.v = e
l.z = j
l.p = n
a.q = e
j.x = d
j.t = n
j.o = b
j.q = e
i.t = j
i.y = j
i.r = a
i.s = d
i.x = b
b.x = e
b.p = d
b.u = i
b.q = n
b.w = l
assert i.x.w.u.txt == "
class A:
    def __init__(self, txt: str):
        self.w: C = None
        self.y: F = None
        self.x: F = None
        self.t: E = None
        self.s: H = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.x: G = None
        self.u: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: I = None
        self.q: A = None
        self.t: H = None
        self.v: D = None
        self.p: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: F = None
        self.q: F = None
        self.t: A = None
        self.v: I = None
        self.y: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: D = None
        self.y: D = None
        self.z: G = None
        self.p: C = None
        self.v: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: A = None
        self.t: C = None
        self.o: I = None
        self.q: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: G = None
        self.r: F = None
        self.y: G = None
        self.s: A = None
        self.x: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: D = None
        self.p: A = None
        self.u: H = None
        self.q: C = None
        self.w: E = None
        self.txt = txt

d = A("d")
h = B("h")
n = C("n")
e = D("e")
l = E("l")
a = F("a")
j = G("j")
i = H("i")
b = I("b")

d.w = n
d.y = a
d.x = a
d.u = a
d.t = l
d.s = i
h.v = j
h.x = j
h.u = j
n.o = b
n.q = d
n.t = i
n.v = e
n.p = e
e.w = l
e.r = a
e.q = a
e.t = d
e.v = b
e.y = n
l.u = h
l.r = e
l.y = e
l.v = e
l.z = j
l.p = n
a.q = e
j.x = d
j.t = n
j.o = b
j.q = e
i.t = j
i.y = j
i.r = a
i.s = d
i.x = b
b.x = e
b.p = d
b.u = i
b.q = n
b.w = l
assert i.x.w.u.txt == "h"