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

class B:
    def __init__(self, txt: str):
        self.o: D = None
        self.z: D = None
        self.t: H = None
        self.r: F = None
        self.w: A = None
        self.s: I = None
        self.u: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.q: A = None
        self.o: D = None
        self.t: D = None
        self.r: D = None
        self.y: H = None
        self.p: F = None
        self.x: E = None
        self.u: A = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: A = None
        self.o: J = None
        self.p: I = None
        self.s: F = None
        self.v: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: B = None
        self.u: F = None
        self.v: G = None
        self.s: G = None
        self.r: H = None
        self.o: A = None
        self.y: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.o: D = None
        self.z: D = None
        self.t: H = None
        self.r: F = None
        self.w: A = None
        self.s: I = None
        self.u: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.q: A = None
        self.o: D = None
        self.t: D = None
        self.r: D = None
        self.y: H = None
        self.p: F = None
        self.x: E = None
        self.u: A = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: A = None
        self.o: J = None
        self.p: I = None
        self.s: F = None
        self.v: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: B = None
        self.u: F = None
        self.v: G = None
        self.s: G = None
        self.r: H = None
        self.o: A = None
        self.y: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

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

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