class A:
    def __init__(self, txt: str):
        self.y: E = None
        self.p: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: C = None
        self.s: F = None
        self.z: B = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: A = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: C = None
        self.s: F = None
        self.z: B = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: A = None
        self.txt = txt

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

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

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

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