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

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

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

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

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

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

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

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

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

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

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

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

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

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

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