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

class B:
    def __init__(self, txt: str):
        self.o: C = None
        self.y: I = None
        self.w: A = None
        self.v: D = None
        self.s: D = None
        self.r: E = None
        self.p: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.t: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.o: C = None
        self.y: I = None
        self.w: A = None
        self.v: D = None
        self.s: D = None
        self.r: E = None
        self.p: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.t: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: D = None
        self.txt = txt

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

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