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

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

class C:
    def __init__(self, txt: str):
        self.v: B = None
        self.z: G = None
        self.y: H = None
        self.x: A = None
        self.s: F = None
        self.q: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: G = None
        self.y: I = None
        self.q: A = None
        self.r: F = None
        self.o: H = None
        self.z: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: G = None
        self.u: B = None
        self.v: C = None
        self.s: I = None
        self.z: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: C = None
        self.t: I = None
        self.z: C = None
        self.q: C = None
        self.r: E = None
        self.y: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: C = None
        self.x: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.t: B = None
        self.p: A = None
        self.o: E = None
        self.txt = txt

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

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

b.s = h
l.s = i
l.q = i
l.r = g
l.t = g
h.v = l
h.q = l
h.z = c
h.y = n
h.x = b
h.s = e
j.v = c
j.y = i
j.q = b
j.r = e
j.o = n
j.z = n
g.q = c
g.u = l
g.v = h
g.s = i
g.z = e
e.s = h
e.z = h
e.q = h
e.t = i
e.r = g
e.y = g
c.y = h
c.x = j
n.r = c
n.t = l
n.p = b
n.o = g
i.y = b
i.v = e
i.z = c
assert l.t.s.z.y.s.t.v.txt == "
class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.v: B = None
        self.z: G = None
        self.y: H = None
        self.x: A = None
        self.s: F = None
        self.q: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: G = None
        self.y: I = None
        self.q: A = None
        self.r: F = None
        self.o: H = None
        self.z: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: G = None
        self.u: B = None
        self.v: C = None
        self.s: I = None
        self.z: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: C = None
        self.t: I = None
        self.z: C = None
        self.q: C = None
        self.r: E = None
        self.y: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: C = None
        self.x: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.t: B = None
        self.p: A = None
        self.o: E = None
        self.txt = txt

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

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

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