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

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

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

class D:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: G = None
        self.v: C = None
        self.y: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.r: C = None
        self.o: D = None
        self.z: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.u: C = None
        self.x: D = None
        self.w: D = None
        self.p: G = None
        self.y: D = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: G = None
        self.v: C = None
        self.y: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.r: C = None
        self.o: D = None
        self.z: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.u: C = None
        self.x: D = None
        self.w: D = None
        self.p: G = None
        self.y: D = None
        self.txt = txt

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

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