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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.s: G = None
        self.y: B = None
        self.q: A = None
        self.v: D = None
        self.w: B = None
        self.x: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: F = None
        self.t: G = None
        self.q: G = None
        self.u: F = None
        self.o: A = None
        self.txt = txt

k = A("k")
n = B("n")
b = C("b")
l = D("l")
g = E("g")
j = F("j")
h = G("h")
e = C("e")
f = G("f")
m = B("m")

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.s: G = None
        self.y: B = None
        self.q: A = None
        self.v: D = None
        self.w: B = None
        self.x: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: F = None
        self.t: G = None
        self.q: G = None
        self.u: F = None
        self.o: A = None
        self.txt = txt

k = A("k")
n = B("n")
b = C("b")
l = D("l")
g = E("g")
j = F("j")
h = G("h")
e = C("e")
f = G("f")
m = B("m")

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