class A:
    def __init__(self, txt: str):
        self.z: C = None
        self.w: A = None
        self.r: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.p: E = None
        self.v: D = None
        self.r: B = None
        self.u: B = None
        self.x: C = None
        self.txt = txt

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

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.p: E = None
        self.v: D = None
        self.r: B = None
        self.u: B = None
        self.x: C = None
        self.txt = txt

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

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

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

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

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

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