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

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

class C:
    def __init__(self, txt: str):
        self.w: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: H = None
        self.r: J = None
        self.u: A = None
        self.s: H = None
        self.z: G = None
        self.w: D = None
        self.v: D = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.v: D = None
        self.p: I = None
        self.z: B = None
        self.t: I = None
        self.y: H = None
        self.o: D = None
        self.q: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.q: J = None
        self.r: H = None
        self.o: J = None
        self.u: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: I = None
        self.o: G = None
        self.w: E = None
        self.y: B = None
        self.x: D = None
        self.t: E = None
        self.s: B = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: H = None
        self.r: J = None
        self.u: A = None
        self.s: H = None
        self.z: G = None
        self.w: D = None
        self.v: D = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.v: D = None
        self.p: I = None
        self.z: B = None
        self.t: I = None
        self.y: H = None
        self.o: D = None
        self.q: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.q: J = None
        self.r: H = None
        self.o: J = None
        self.u: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: I = None
        self.o: G = None
        self.w: E = None
        self.y: B = None
        self.x: D = None
        self.t: E = None
        self.s: B = None
        self.txt = txt

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

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

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

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