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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.p: A = None
        self.u: B = None
        self.y: A = None
        self.w: C = None
        self.z: C = None
        self.txt = txt

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.p: A = None
        self.u: B = None
        self.y: A = None
        self.w: C = None
        self.z: C = None
        self.txt = txt

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

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