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

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

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.y: I = None
        self.o: D = None
        self.r: H = None
        self.x: F = None
        self.q: E = None
        self.p: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.w: F = None
        self.z: G = None
        self.y: E = None
        self.u: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.r: H = None
        self.p: C = None
        self.t: B = None
        self.y: B = None
        self.s: D = None
        self.x: H = None
        self.u: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: F = None
        self.r: C = None
        self.t: D = None
        self.w: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: C = None
        self.x: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.y: I = None
        self.o: D = None
        self.r: H = None
        self.x: F = None
        self.q: E = None
        self.p: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.w: F = None
        self.z: G = None
        self.y: E = None
        self.u: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.r: H = None
        self.p: C = None
        self.t: B = None
        self.y: B = None
        self.s: D = None
        self.x: H = None
        self.u: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: F = None
        self.r: C = None
        self.t: D = None
        self.w: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: C = None
        self.x: F = None
        self.txt = txt

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

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