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

class B:
    def __init__(self, txt: str):
        self.x: I = None
        self.p: G = None
        self.r: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.q: A = None
        self.s: E = None
        self.y: E = None
        self.x: H = None
        self.v: G = None
        self.o: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.t: G = None
        self.s: G = None
        self.u: A = None
        self.v: C = None
        self.w: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: I = None
        self.r: F = None
        self.x: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: B = None
        self.s: C = None
        self.o: E = None
        self.r: C = None
        self.v: A = None
        self.z: B = None
        self.q: C = None
        self.txt = txt

d = A("d")
k = B("k")
m = C("m")
h = D("h")
e = E("e")
j = F("j")
f = G("f")
c = H("c")
l = I("l")
g = H("g")

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

class B:
    def __init__(self, txt: str):
        self.x: I = None
        self.p: G = None
        self.r: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.q: A = None
        self.s: E = None
        self.y: E = None
        self.x: H = None
        self.v: G = None
        self.o: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.t: G = None
        self.s: G = None
        self.u: A = None
        self.v: C = None
        self.w: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: I = None
        self.r: F = None
        self.x: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: B = None
        self.s: C = None
        self.o: E = None
        self.r: C = None
        self.v: A = None
        self.z: B = None
        self.q: C = None
        self.txt = txt

d = A("d")
k = B("k")
m = C("m")
h = D("h")
e = E("e")
j = F("j")
f = G("f")
c = H("c")
l = I("l")
g = H("g")

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