class A:
    def __init__(self, txt: str):
        self.q: C = None
        self.p: D = None
        self.x: H = None
        self.r: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.w: D = None
        self.s: D = None
        self.x: E = None
        self.t: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: G = None
        self.v: B = None
        self.q: H = None
        self.t: B = None
        self.p: F = None
        self.w: F = None
        self.x: I = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.z: A = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.w: D = None
        self.s: D = None
        self.x: E = None
        self.t: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: G = None
        self.v: B = None
        self.q: H = None
        self.t: B = None
        self.p: F = None
        self.w: F = None
        self.x: I = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.z: A = None
        self.txt = txt

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

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

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

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