class A:
    def __init__(self, txt: str):
        self.y: F = None
        self.z: G = None
        self.u: E = None
        self.s: C = None
        self.t: F = None
        self.w: E = None
        self.o: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: F = None
        self.o: C = None
        self.v: G = None
        self.u: C = None
        self.x: H = None
        self.s: C = None
        self.p: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: B = None
        self.r: A = None
        self.p: G = None
        self.t: B = None
        self.v: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.s: H = None
        self.r: G = None
        self.x: B = None
        self.q: D = None
        self.u: F = None
        self.o: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: H = None
        self.o: F = None
        self.t: A = None
        self.s: H = None
        self.x: A = None
        self.p: H = None
        self.w: B = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.r: F = None
        self.o: C = None
        self.v: G = None
        self.u: C = None
        self.x: H = None
        self.s: C = None
        self.p: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: B = None
        self.r: A = None
        self.p: G = None
        self.t: B = None
        self.v: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.s: H = None
        self.r: G = None
        self.x: B = None
        self.q: D = None
        self.u: F = None
        self.o: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: H = None
        self.o: F = None
        self.t: A = None
        self.s: H = None
        self.x: A = None
        self.p: H = None
        self.w: B = None
        self.txt = txt

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

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

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