class A:
    def __init__(self, txt: str):
        self.x: D = None
        self.o: E = None
        self.y: D = None
        self.p: B = None
        self.u: B = None
        self.q: G = None
        self.v: I = None
        self.z: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: B = None
        self.w: F = None
        self.q: F = None
        self.x: E = None
        self.t: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.z: H = None
        self.s: I = None
        self.x: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: B = None
        self.u: G = None
        self.w: C = None
        self.z: H = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: C = None
        self.x: A = None
        self.t: B = None
        self.z: D = None
        self.v: G = None
        self.u: G = None
        self.txt = txt

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

i.x = m
i.y = m
i.o = f
i.p = e
i.u = e
i.q = d
i.v = g
i.z = k
e.u = i
e.t = f
e.p = b
b.o = e
b.w = j
b.q = j
b.x = f
b.t = g
m.s = j
m.u = b
f.w = g
f.s = g
f.x = g
f.z = l
j.u = e
j.y = i
j.q = i
j.r = i
d.t = g
l.v = e
l.u = d
l.w = b
l.z = k
g.r = b
g.x = i
g.t = e
g.z = m
g.v = d
g.u = d
k.v = e
k.u = d
k.w = b
k.z = l
assert e.u.p.u.p.t.z.txt == "
class A:
    def __init__(self, txt: str):
        self.x: D = None
        self.o: E = None
        self.y: D = None
        self.p: B = None
        self.u: B = None
        self.q: G = None
        self.v: I = None
        self.z: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: B = None
        self.w: F = None
        self.q: F = None
        self.x: E = None
        self.t: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.z: H = None
        self.s: I = None
        self.x: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: B = None
        self.u: G = None
        self.w: C = None
        self.z: H = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: C = None
        self.x: A = None
        self.t: B = None
        self.z: D = None
        self.v: G = None
        self.u: G = None
        self.txt = txt

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

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