class A:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: E = None
        self.t: E = None
        self.r: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: G = None
        self.y: B = None
        self.p: G = None
        self.r: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.t: A = None
        self.o: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.t: A = None
        self.y: B = None
        self.txt = txt

c = A("c")
e = B("e")
d = C("d")
b = D("b")
i = E("i")
l = F("l")
k = G("k")
n = D("n")
j = C("j")
g = F("g")

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

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

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: G = None
        self.y: B = None
        self.p: G = None
        self.r: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.t: A = None
        self.o: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.t: A = None
        self.y: B = None
        self.txt = txt

c = A("c")
e = B("e")
d = C("d")
b = D("b")
i = E("i")
l = F("l")
k = G("k")
n = D("n")
j = C("j")
g = F("g")

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