class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.v: B = None
        self.r: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.o: B = None
        self.r: C = None
        self.w: E = None
        self.u: B = None
        self.t: C = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.w: C = None
        self.r: A = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.o: B = None
        self.r: C = None
        self.w: E = None
        self.u: B = None
        self.t: C = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.w: C = None
        self.r: A = None
        self.txt = txt

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

i.t = f
i.r = f
i.v = c
c.y = g
c.v = f
c.x = f
c.r = k
c.w = k
c.u = h
b.y = k
b.o = c
b.u = c
b.r = h
b.t = h
b.w = g
k.v = g
k.z = c
k.s = c
k.y = j
e.s = j
e.v = k
e.z = m
f.w = h
f.r = i
j.t = f
j.r = f
j.v = c
g.s = i
g.v = k
g.z = m
h.y = k
h.o = c
h.u = c
h.r = b
h.t = b
h.w = e
m.s = j
m.v = k
m.z = e
assert e.v.s.y.s.t.r.v.txt == "c"