class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: D = None
        self.o: I = None
        self.z: I = None
        self.p: D = None
        self.y: D = None
        self.u: I = None
        self.w: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: C = None
        self.r: F = None
        self.t: D = None
        self.q: H = None
        self.v: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: C = None
        self.o: C = None
        self.p: G = None
        self.u: G = None
        self.w: A = None
        self.q: I = None
        self.t: D = None
        self.z: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.y: F = None
        self.w: F = None
        self.p: H = None
        self.v: F = None
        self.r: B = None
        self.q: H = None
        self.t: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: B = None
        self.o: H = None
        self.y: F = None
        self.s: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: E = None
        self.t: D = None
        self.txt = txt

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

g.v = d
g.t = m
g.p = m
g.y = m
g.o = b
g.z = b
g.u = b
g.w = a
a.x = d
a.r = i
a.t = m
a.v = m
a.q = k
d.x = a
d.u = g
m.v = j
m.p = k
j.y = d
j.o = d
j.p = h
j.u = h
j.w = g
j.z = g
j.q = b
j.t = m
i.q = m
i.t = d
i.u = d
i.s = d
i.y = b
i.o = c
i.v = a
i.w = j
h.u = c
h.p = c
h.y = i
h.w = i
h.v = i
h.r = a
h.q = k
h.t = b
c.t = a
c.o = k
c.y = i
c.s = g
b.o = j
b.t = m
k.t = a
k.o = c
k.y = i
k.s = g
assert g.v.x.r.s.u.w.x.u.o.txt == "
class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: D = None
        self.o: I = None
        self.z: I = None
        self.p: D = None
        self.y: D = None
        self.u: I = None
        self.w: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: C = None
        self.r: F = None
        self.t: D = None
        self.q: H = None
        self.v: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: C = None
        self.o: C = None
        self.p: G = None
        self.u: G = None
        self.w: A = None
        self.q: I = None
        self.t: D = None
        self.z: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.y: F = None
        self.w: F = None
        self.p: H = None
        self.v: F = None
        self.r: B = None
        self.q: H = None
        self.t: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: B = None
        self.o: H = None
        self.y: F = None
        self.s: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: E = None
        self.t: D = None
        self.txt = txt

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

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