class A:
    def __init__(self, txt: str):
        self.q: C = None
        self.t: D = None
        self.s: A = None
        self.r: D = None
        self.o: A = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

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

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

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

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