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

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

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

class D:
    def __init__(self, txt: str):
        self.r: F = None
        self.y: C = None
        self.w: F = None
        self.x: B = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: F = None
        self.r: C = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.r: F = None
        self.y: C = None
        self.w: F = None
        self.x: B = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: F = None
        self.r: C = None
        self.txt = txt

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

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