class A:
    def __init__(self, txt: str):
        self.v: D = None
        self.z: I = None
        self.p: G = None
        self.o: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: F = None
        self.y: F = None
        self.t: A = None
        self.w: A = None
        self.v: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: B = None
        self.r: E = None
        self.p: F = None
        self.q: I = None
        self.y: H = None
        self.w: G = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.w: G = None
        self.t: A = None
        self.q: G = None
        self.p: I = None
        self.x: D = None
        self.s: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: I = None
        self.v: I = None
        self.o: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: D = None
        self.x: G = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: F = None
        self.y: F = None
        self.t: A = None
        self.w: A = None
        self.v: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: B = None
        self.r: E = None
        self.p: F = None
        self.q: I = None
        self.y: H = None
        self.w: G = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.w: G = None
        self.t: A = None
        self.q: G = None
        self.p: I = None
        self.x: D = None
        self.s: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: I = None
        self.v: I = None
        self.o: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: D = None
        self.x: G = None
        self.txt = txt

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

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