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

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.u: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: I = None
        self.r: B = None
        self.y: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: D = None
        self.v: F = None
        self.z: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: F = None
        self.q: A = None
        self.y: B = None
        self.p: C = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.u: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: I = None
        self.r: B = None
        self.y: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: D = None
        self.v: F = None
        self.z: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: F = None
        self.q: A = None
        self.y: B = None
        self.p: C = None
        self.txt = txt

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

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