class A:
    def __init__(self, txt: str):
        self.q: C = None
        self.u: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.s: F = None
        self.v: B = None
        self.p: E = None
        self.y: C = None
        self.t: D = None
        self.z: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.w: B = None
        self.t: B = None
        self.u: E = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: C = None
        self.y: E = None
        self.o: E = None
        self.txt = txt

b = A("b")
l = B("l")
j = C("j")
n = D("n")
k = E("k")
i = F("i")
a = C("a")
g = E("g")
m = D("m")
d = B("d")

b.q = a
b.u = n
l.o = b
l.q = b
j.s = a
j.r = a
j.w = k
j.u = i
j.p = b
j.z = n
n.s = i
n.v = l
n.p = k
n.y = a
n.t = m
n.z = m
k.o = a
k.w = d
k.t = l
k.u = g
i.v = a
i.y = k
i.o = k
a.s = j
a.r = j
a.w = k
a.u = i
a.p = b
a.z = n
g.o = a
g.w = l
g.t = d
g.u = k
m.s = i
m.v = d
m.p = k
m.y = j
m.t = n
m.z = n
d.o = b
d.q = b
assert i.y.w.q.u.v.o.u.p.txt == "
class A:
    def __init__(self, txt: str):
        self.q: C = None
        self.u: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.s: F = None
        self.v: B = None
        self.p: E = None
        self.y: C = None
        self.t: D = None
        self.z: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.w: B = None
        self.t: B = None
        self.u: E = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: C = None
        self.y: E = None
        self.o: E = None
        self.txt = txt

b = A("b")
l = B("l")
j = C("j")
n = D("n")
k = E("k")
i = F("i")
a = C("a")
g = E("g")
m = D("m")
d = B("d")

b.q = a
b.u = n
l.o = b
l.q = b
j.s = a
j.r = a
j.w = k
j.u = i
j.p = b
j.z = n
n.s = i
n.v = l
n.p = k
n.y = a
n.t = m
n.z = m
k.o = a
k.w = d
k.t = l
k.u = g
i.v = a
i.y = k
i.o = k
a.s = j
a.r = j
a.w = k
a.u = i
a.p = b
a.z = n
g.o = a
g.w = l
g.t = d
g.u = k
m.s = i
m.v = d
m.p = k
m.y = j
m.t = n
m.z = n
d.o = b
d.q = b
assert i.y.w.q.u.v.o.u.p.txt == "k"