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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.p: G = None
        self.u: I = None
        self.o: G = None
        self.v: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: F = None
        self.p: H = None
        self.r: H = None
        self.txt = txt

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

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

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.p: G = None
        self.u: I = None
        self.o: G = None
        self.v: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: F = None
        self.p: H = None
        self.r: H = None
        self.txt = txt

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

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

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

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