class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.v: E = None
        self.z: F = None
        self.o: B = None
        self.x: C = None
        self.r: G = None
        self.y: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.t: E = None
        self.s: E = None
        self.q: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: B = None
        self.x: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: B = None
        self.w: D = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.t: E = None
        self.s: E = None
        self.q: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: B = None
        self.x: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: B = None
        self.w: D = None
        self.txt = txt

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

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

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

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