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

class B:
    def __init__(self, txt: str):
        self.y: C = None
        self.x: G = None
        self.v: D = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.y: I = None
        self.p: I = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: E = None
        self.q: C = None
        self.y: A = None
        self.p: E = None
        self.x: C = None
        self.r: H = None
        self.o: E = None
        self.u: C = None
        self.txt = txt

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

i.z = m
i.y = g
i.w = g
i.v = a
i.u = b
m.y = e
m.x = d
m.v = f
e.q = d
e.s = d
e.p = m
e.v = m
e.r = j
f.v = e
f.q = i
b.r = g
g.p = a
g.u = a
g.r = d
g.w = b
d.s = f
d.y = j
d.p = j
a.q = g
a.s = m
a.w = d
j.v = b
j.p = b
j.o = b
j.q = e
j.x = e
j.u = e
j.y = i
j.r = a
assert e.p.y.s.txt == "
class A:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: F = None
        self.w: F = None
        self.v: H = None
        self.u: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: C = None
        self.x: G = None
        self.v: D = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.y: I = None
        self.p: I = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: E = None
        self.q: C = None
        self.y: A = None
        self.p: E = None
        self.x: C = None
        self.r: H = None
        self.o: E = None
        self.u: C = None
        self.txt = txt

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

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