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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.q: E = None
        self.w: F = None
        self.s: E = None
        self.x: H = None
        self.r: I = None
        self.t: F = None
        self.z: F = None
        self.p: C = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.v: B = None
        self.q: G = None
        self.w: G = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.q: E = None
        self.w: F = None
        self.s: E = None
        self.x: H = None
        self.r: I = None
        self.t: F = None
        self.z: F = None
        self.p: C = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.v: B = None
        self.q: G = None
        self.w: G = None
        self.txt = txt

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

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

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

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

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