class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.z: E = None
        self.q: C = None
        self.x: F = None
        self.y: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.y: E = None
        self.p: A = None
        self.u: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: E = None
        self.r: F = None
        self.txt = txt

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

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

j = A("j")
m = B("m")
a = C("a")
e = D("e")
f = E("f")
i = F("i")
g = C("g")
c = E("c")

j.t = m
j.y = m
j.z = f
j.q = g
j.x = i
m.u = g
m.t = e
a.o = i
a.y = c
a.p = j
a.u = j
e.u = m
e.z = f
e.r = i
f.x = i
f.w = i
f.t = i
f.p = m
f.r = g
f.s = c
i.v = e
g.o = i
g.y = c
g.p = j
g.u = j
c.x = i
c.w = i
c.t = i
c.p = m
c.r = a
c.s = f
assert i.v.z.p.u.o.txt == "
class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.z: E = None
        self.q: C = None
        self.x: F = None
        self.y: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.y: E = None
        self.p: A = None
        self.u: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: E = None
        self.r: F = None
        self.txt = txt

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

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

j = A("j")
m = B("m")
a = C("a")
e = D("e")
f = E("f")
i = F("i")
g = C("g")
c = E("c")

j.t = m
j.y = m
j.z = f
j.q = g
j.x = i
m.u = g
m.t = e
a.o = i
a.y = c
a.p = j
a.u = j
e.u = m
e.z = f
e.r = i
f.x = i
f.w = i
f.t = i
f.p = m
f.r = g
f.s = c
i.v = e
g.o = i
g.y = c
g.p = j
g.u = j
c.x = i
c.w = i
c.t = i
c.p = m
c.r = a
c.s = f
assert i.v.z.p.u.o.txt == "i"