class A:
    def __init__(self, txt: str):
        self.y: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: A = None
        self.r: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.v: F = None
        self.q: H = None
        self.txt = txt

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

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

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

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: A = None
        self.r: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.v: F = None
        self.q: H = None
        self.txt = txt

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

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

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

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

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

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

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

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