class A:
    def __init__(self, txt: str):
        self.v: E = None
        self.w: E = None
        self.y: C = None
        self.s: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.t: B = None
        self.x: C = None
        self.o: D = None
        self.s: B = None
        self.z: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.y: F = None
        self.s: A = None
        self.w: D = None
        self.o: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: C = None
        self.txt = txt

i = A("i")
h = B("h")
g = C("g")
j = D("j")
m = E("m")
l = F("l")
b = E("b")
e = D("e")
k = B("k")
c = F("c")

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

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

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

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.t: B = None
        self.x: C = None
        self.o: D = None
        self.s: B = None
        self.z: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.y: F = None
        self.s: A = None
        self.w: D = None
        self.o: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: C = None
        self.txt = txt

i = A("i")
h = B("h")
g = C("g")
j = D("j")
m = E("m")
l = F("l")
b = E("b")
e = D("e")
k = B("k")
c = F("c")

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