class A:
    def __init__(self, txt: str):
        self.v: E = None
        self.o: G = None
        self.u: D = None
        self.w: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.p: E = None
        self.x: F = None
        self.u: J = None
        self.o: C = None
        self.v: B = None
        self.r: C = None
        self.z: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.v: H = None
        self.o: D = None
        self.t: G = None
        self.s: I = None
        self.z: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: C = None
        self.p: D = None
        self.s: F = None
        self.o: I = None
        self.z: F = None
        self.y: D = None
        self.t: I = None
        self.u: D = None
        self.v: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: H = None
        self.t: G = None
        self.y: G = None
        self.u: C = None
        self.w: G = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.p: E = None
        self.x: F = None
        self.u: J = None
        self.o: C = None
        self.v: B = None
        self.r: C = None
        self.z: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.v: H = None
        self.o: D = None
        self.t: G = None
        self.s: I = None
        self.z: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: C = None
        self.p: D = None
        self.s: F = None
        self.o: I = None
        self.z: F = None
        self.y: D = None
        self.t: I = None
        self.u: D = None
        self.v: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: H = None
        self.t: G = None
        self.y: G = None
        self.u: C = None
        self.w: G = None
        self.txt = txt

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

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

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