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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: G = None
        self.p: H = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.v: F = None
        self.p: B = None
        self.q: H = None
        self.t: C = None
        self.z: B = None
        self.s: E = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: G = None
        self.p: H = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.v: F = None
        self.p: B = None
        self.q: H = None
        self.t: C = None
        self.z: B = None
        self.s: E = None
        self.txt = txt

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

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

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