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

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

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.w: G = None
        self.u: E = None
        self.t: D = None
        self.v: I = None
        self.s: C = None
        self.r: G = None
        self.z: A = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.w: G = None
        self.u: E = None
        self.t: D = None
        self.v: I = None
        self.s: C = None
        self.r: G = None
        self.z: A = None
        self.txt = txt

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

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

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

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

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