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

class B:
    def __init__(self, txt: str):
        self.w: I = None
        self.x: A = None
        self.u: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.s: C = None
        self.y: A = None
        self.z: C = None
        self.o: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: D = None
        self.p: A = None
        self.r: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: I = None
        self.u: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: A = None
        self.w: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: E = None
        self.v: A = None
        self.x: E = None
        self.z: D = None
        self.q: C = None
        self.y: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.w: I = None
        self.x: A = None
        self.u: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: I = None
        self.s: C = None
        self.y: A = None
        self.z: C = None
        self.o: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: D = None
        self.p: A = None
        self.r: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: I = None
        self.u: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: A = None
        self.w: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: E = None
        self.v: A = None
        self.x: E = None
        self.z: D = None
        self.q: C = None
        self.y: C = None
        self.txt = txt

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

a.v = j
a.x = j
a.u = l
a.q = b
a.r = g
a.y = n
i.w = f
i.x = a
i.u = l
n.q = j
n.w = b
k.x = f
k.s = n
k.z = n
k.y = a
k.o = a
j.x = k
j.p = a
j.r = n
l.w = f
g.v = f
g.u = l
b.p = a
b.w = f
f.w = j
f.x = j
f.v = a
f.z = k
f.q = n
f.y = n
assert g.u.w.v.y.q.txt == "j"