class A:
    def __init__(self, txt: str):
        self.s: D = None
        self.v: E = None
        self.r: G = None
        self.x: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.t: G = None
        self.s: G = None
        self.x: H = None
        self.q: H = None
        self.v: D = None
        self.o: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.o: H = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: A = None
        self.r: A = None
        self.w: B = None
        self.z: G = None
        self.q: B = None
        self.p: I = None
        self.o: H = None
        self.u: G = None
        self.s: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.s: I = None
        self.u: C = None
        self.t: B = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: C = None
        self.r: G = None
        self.y: F = None
        self.p: I = None
        self.x: G = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.t: G = None
        self.s: G = None
        self.x: H = None
        self.q: H = None
        self.v: D = None
        self.o: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.o: H = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: A = None
        self.r: A = None
        self.w: B = None
        self.z: G = None
        self.q: B = None
        self.p: I = None
        self.o: H = None
        self.u: G = None
        self.s: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.s: I = None
        self.u: C = None
        self.t: B = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: C = None
        self.r: G = None
        self.y: F = None
        self.p: I = None
        self.x: G = None
        self.txt = txt

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

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

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