class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

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

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

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

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