class A:
    def __init__(self, txt: str):
        self.q: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.q: F = None
        self.z: E = None
        self.u: F = None
        self.v: H = None
        self.t: A = None
        self.y: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: B = None
        self.w: A = None
        self.v: C = None
        self.p: I = None
        self.r: B = None
        self.o: F = None
        self.x: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: H = None
        self.w: H = None
        self.p: A = None
        self.u: C = None
        self.o: G = None
        self.r: H = None
        self.v: H = None
        self.q: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: I = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.q: F = None
        self.z: E = None
        self.u: F = None
        self.v: H = None
        self.t: A = None
        self.y: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: B = None
        self.w: A = None
        self.v: C = None
        self.p: I = None
        self.r: B = None
        self.o: F = None
        self.x: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: H = None
        self.w: H = None
        self.p: A = None
        self.u: C = None
        self.o: G = None
        self.r: H = None
        self.v: H = None
        self.q: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: I = None
        self.txt = txt

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

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

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

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

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