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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.w: E = None
        self.v: F = None
        self.o: D = None
        self.p: A = None
        self.t: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: D = None
        self.x: F = None
        self.q: B = None
        self.t: I = None
        self.p: I = None
        self.u: C = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.w: E = None
        self.v: F = None
        self.o: D = None
        self.p: A = None
        self.t: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: D = None
        self.x: F = None
        self.q: B = None
        self.t: I = None
        self.p: I = None
        self.u: C = None
        self.txt = txt

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

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

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

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