class A:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: D = None
        self.o: A = None
        self.z: F = None
        self.v: E = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

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

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

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

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