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

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.s: C = None
        self.r: H = None
        self.v: F = None
        self.u: A = None
        self.q: F = None
        self.p: D = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.u: E = None
        self.t: E = None
        self.z: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: A = None
        self.x: D = None
        self.t: H = None
        self.z: C = None
        self.v: G = None
        self.o: C = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.s: C = None
        self.r: H = None
        self.v: F = None
        self.u: A = None
        self.q: F = None
        self.p: D = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.u: E = None
        self.t: E = None
        self.z: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: A = None
        self.x: D = None
        self.t: H = None
        self.z: C = None
        self.v: G = None
        self.o: C = None
        self.txt = txt

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

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

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