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

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

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.z: B = None
        self.y: A = None
        self.q: D = None
        self.x: D = None
        self.t: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.y: A = None
        self.r: C = None
        self.t: D = None
        self.s: F = None
        self.v: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.z: B = None
        self.y: A = None
        self.q: D = None
        self.x: D = None
        self.t: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.y: A = None
        self.r: C = None
        self.t: D = None
        self.s: F = None
        self.v: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.txt = txt

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

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

j.v = g
j.r = h
k.o = i
k.x = j
k.q = j
k.v = h
k.s = d
d.s = h
d.z = g
d.y = j
d.q = i
d.x = i
d.t = i
i.x = g
i.v = g
i.y = j
i.r = d
i.t = l
i.s = h
f.z = d
h.o = j
h.z = l
h.t = d
h.x = f
b.o = j
b.z = l
b.t = d
b.x = f
l.x = g
l.v = g
l.y = j
l.r = d
l.t = i
l.s = h
c.o = j
c.z = i
c.t = d
c.x = f
g.o = i
g.x = j
g.q = j
g.v = b
g.s = d
assert d.q.r.y.v.s.z.o.r.z.v.txt == "b"