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

class B:
    def __init__(self, txt: str):
        self.t: A = None
        self.q: E = None
        self.u: E = None
        self.w: F = None
        self.v: E = None
        self.txt = txt

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

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.t: A = None
        self.q: E = None
        self.u: E = None
        self.w: F = None
        self.v: E = None
        self.txt = txt

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

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

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

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

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

l.s = b
l.y = n
l.v = a
g.t = m
g.q = i
g.u = i
g.v = i
g.w = n
a.x = e
a.u = n
a.v = j
a.r = g
j.u = k
j.x = a
i.s = m
i.y = b
n.y = a
n.q = a
n.x = k
n.s = k
n.w = l
n.r = i
k.u = j
k.x = a
b.y = a
b.q = a
b.x = j
b.s = k
b.w = m
b.r = i
m.s = n
m.y = n
m.v = a
e.t = l
e.q = i
e.u = i
e.v = i
e.w = n
assert n.s.x.v.x.x.t.v.x.txt == "e"