class A:
    def __init__(self, txt: str):
        self.u: B = None
        self.s: D = None
        self.w: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.y: E = None
        self.t: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: E = None
        self.r: F = None
        self.s: A = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.y: E = None
        self.t: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: E = None
        self.r: F = None
        self.s: A = None
        self.txt = txt

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

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