class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.q: C = None
        self.t: D = None
        self.w: E = None
        self.p: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: A = None
        self.u: B = None
        self.x: F = None
        self.s: E = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: A = None
        self.u: B = None
        self.x: F = None
        self.s: E = None
        self.txt = txt

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

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

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

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