class A:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: D = None
        self.t: G = None
        self.s: I = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: A = None
        self.q: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: B = None
        self.s: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.t: B = None
        self.v: E = None
        self.p: F = None
        self.s: C = None
        self.y: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: B = None
        self.w: G = None
        self.r: G = None
        self.u: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: A = None
        self.q: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: B = None
        self.s: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.t: B = None
        self.v: E = None
        self.p: F = None
        self.s: C = None
        self.y: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: B = None
        self.w: G = None
        self.r: G = None
        self.u: D = None
        self.txt = txt

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

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