class A:
    def __init__(self, txt: str):
        self.t: E = None
        self.x: F = None
        self.p: A = None
        self.w: H = None
        self.z: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: D = None
        self.u: H = None
        self.o: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.p: F = None
        self.z: E = None
        self.o: E = None
        self.u: F = None
        self.s: F = None
        self.y: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: A = None
        self.o: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: C = None
        self.v: E = None
        self.y: D = None
        self.z: C = None
        self.w: B = None
        self.p: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: D = None
        self.u: H = None
        self.o: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.p: F = None
        self.z: E = None
        self.o: E = None
        self.u: F = None
        self.s: F = None
        self.y: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: A = None
        self.o: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: C = None
        self.v: E = None
        self.y: D = None
        self.z: C = None
        self.w: B = None
        self.p: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

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