class A:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: B = None
        self.x: D = None
        self.u: B = None
        self.s: G = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.t: F = None
        self.p: A = None
        self.o: A = None
        self.s: B = None
        self.x: C = None
        self.u: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: F = None
        self.t: E = None
        self.o: D = None
        self.v: A = None
        self.r: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: B = None
        self.x: D = None
        self.u: B = None
        self.s: G = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.t: F = None
        self.p: A = None
        self.o: A = None
        self.s: B = None
        self.x: C = None
        self.u: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: F = None
        self.t: E = None
        self.o: D = None
        self.v: A = None
        self.r: G = None
        self.txt = txt

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

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