class A:
    def __init__(self, txt: str):
        self.x: C = None
        self.v: G = None
        self.w: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.t: G = None
        self.o: E = None
        self.z: E = None
        self.w: B = None
        self.x: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.z: G = None
        self.p: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.s: C = None
        self.q: A = None
        self.t: H = None
        self.r: D = None
        self.o: E = None
        self.p: B = None
        self.u: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.p: B = None
        self.x: G = None
        self.s: C = None
        self.o: C = None
        self.w: E = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.t: G = None
        self.o: E = None
        self.z: E = None
        self.w: B = None
        self.x: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.z: G = None
        self.p: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.s: C = None
        self.q: A = None
        self.t: H = None
        self.r: D = None
        self.o: E = None
        self.p: B = None
        self.u: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.p: B = None
        self.x: G = None
        self.s: C = None
        self.o: C = None
        self.w: E = None
        self.txt = txt

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

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