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

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

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: F = None
        self.w: F = None
        self.s: A = None
        self.y: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.q: E = None
        self.txt = txt

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

b = A("b")
g = B("g")
a = C("a")
n = D("n")
k = E("k")
j = F("j")
f = A("f")
e = E("e")
m = B("m")

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

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

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: F = None
        self.w: F = None
        self.s: A = None
        self.y: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.q: E = None
        self.txt = txt

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

b = A("b")
g = B("g")
a = C("a")
n = D("n")
k = E("k")
j = F("j")
f = A("f")
e = E("e")
m = B("m")

b.t = j
b.p = j
g.t = j
g.u = a
g.o = a
a.o = j
a.v = j
a.w = j
a.s = f
a.y = f
n.u = k
n.q = k
n.w = a
n.t = a
n.y = a
k.x = b
k.q = e
j.q = e
j.s = e
j.y = e
j.v = k
j.x = g
j.u = g
f.t = j
f.p = j
e.x = b
e.q = k
m.t = j
m.u = a
m.o = a
assert m.o.o.v.x.t.v.q.q.txt == "k"