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

class B:
    def __init__(self, txt: str):
        self.o: D = None
        self.q: D = None
        self.r: E = None
        self.x: E = None
        self.y: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.s: B = None
        self.o: B = None
        self.txt = txt

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

e = A("e")
d = B("d")
a = C("a")
i = D("i")
k = E("k")
n = A("n")
m = B("m")
c = D("c")
b = B("b")

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

class B:
    def __init__(self, txt: str):
        self.o: D = None
        self.q: D = None
        self.r: E = None
        self.x: E = None
        self.y: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.s: B = None
        self.o: B = None
        self.txt = txt

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

e = A("e")
d = B("d")
a = C("a")
i = D("i")
k = E("k")
n = A("n")
m = B("m")
c = D("c")
b = B("b")

e.v = b
e.u = b
e.r = a
e.x = d
e.q = c
d.o = i
d.q = c
d.r = k
d.x = k
d.y = k
a.o = i
a.w = n
a.t = n
i.y = m
i.s = d
i.o = b
k.x = b
k.p = a
k.v = e
k.w = m
k.t = i
n.v = b
n.r = a
n.u = d
n.x = m
n.q = c
m.o = c
m.q = i
m.r = k
m.x = k
m.y = k
c.y = b
c.s = b
c.o = b
b.o = c
b.q = c
b.r = k
b.x = k
b.y = k
assert e.u.o.s.q.o.q.y.txt == "b"