class A:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: G = None
        self.v: H = None
        self.t: I = None
        self.q: D = None
        self.r: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.q: I = None
        self.x: H = None
        self.z: D = None
        self.w: B = None
        self.o: H = None
        self.y: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: E = None
        self.s: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.w: E = None
        self.p: G = None
        self.x: E = None
        self.txt = txt

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

c = A("c")
b = B("b")
i = C("i")
a = D("a")
f = E("f")
g = F("g")
l = G("l")
j = H("j")
e = I("e")

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

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

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.q: I = None
        self.x: H = None
        self.z: D = None
        self.w: B = None
        self.o: H = None
        self.y: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: E = None
        self.s: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.w: E = None
        self.p: G = None
        self.x: E = None
        self.txt = txt

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

c = A("c")
b = B("b")
i = C("i")
a = D("a")
f = E("f")
g = F("g")
l = G("l")
j = H("j")
e = I("e")

c.o = e
c.t = e
c.w = l
c.v = j
c.r = j
c.q = a
b.p = l
b.w = j
i.t = g
i.q = e
i.x = j
i.o = j
i.y = j
i.z = a
i.w = b
a.r = f
a.s = f
f.x = c
f.u = i
g.u = i
g.v = c
g.z = c
g.y = b
l.y = b
l.u = c
j.u = l
j.p = l
j.w = f
j.x = f
e.v = g
e.r = g
e.q = g
e.t = j
assert a.s.x.t.t.w.x.txt == "c"