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

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

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

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

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: I = None
        self.y: F = None
        self.o: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: I = None
        self.t: A = None
        self.z: C = None
        self.w: G = None
        self.q: B = None
        self.r: G = None
        self.s: D = None
        self.o: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.x: A = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: I = None
        self.y: F = None
        self.o: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: I = None
        self.t: A = None
        self.z: C = None
        self.w: G = None
        self.q: B = None
        self.r: G = None
        self.s: D = None
        self.o: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.x: A = None
        self.txt = txt

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

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