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

class B:
    def __init__(self, txt: str):
        self.y: F = None
        self.u: E = None
        self.w: D = None
        self.s: D = None
        self.q: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: B = None
        self.q: C = None
        self.y: C = None
        self.x: F = None
        self.txt = txt

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

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

j = A("j")
n = B("n")
m = C("m")
e = D("e")
g = E("g")
f = F("f")
k = E("k")
d = E("d")
b = C("b")
c = C("c")

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

class B:
    def __init__(self, txt: str):
        self.y: F = None
        self.u: E = None
        self.w: D = None
        self.s: D = None
        self.q: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: B = None
        self.q: C = None
        self.y: C = None
        self.x: F = None
        self.txt = txt

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

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

j = A("j")
n = B("n")
m = C("m")
e = D("e")
g = E("g")
f = F("f")
k = E("k")
d = E("d")
b = C("b")
c = C("c")

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