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

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

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

class D:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: G = None
        self.q: E = None
        self.x: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: I = None
        self.y: E = None
        self.w: H = None
        self.u: C = None
        self.t: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: C = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: G = None
        self.q: E = None
        self.x: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: I = None
        self.y: E = None
        self.w: H = None
        self.u: C = None
        self.t: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: C = None
        self.txt = txt

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

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

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

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