class A:
    def __init__(self, txt: str):
        self.v: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.p: E = None
        self.w: B = None
        self.q: A = None
        self.s: C = None
        self.t: B = None
        self.z: G = None
        self.u: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: B = None
        self.z: C = None
        self.p: F = None
        self.y: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.w: H = None
        self.z: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.o: B = None
        self.y: F = None
        self.q: E = None
        self.p: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.p: E = None
        self.w: B = None
        self.q: A = None
        self.s: C = None
        self.t: B = None
        self.z: G = None
        self.u: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: B = None
        self.z: C = None
        self.p: F = None
        self.y: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.w: H = None
        self.z: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.o: B = None
        self.y: F = None
        self.q: E = None
        self.p: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: D = None
        self.txt = txt

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

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