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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: E = None
        self.q: F = None
        self.y: F = None
        self.r: A = None
        self.z: E = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: E = None
        self.q: F = None
        self.y: F = None
        self.r: A = None
        self.z: E = None
        self.txt = txt

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

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

l.v = d
l.y = i
l.u = b
l.z = j
l.q = c
i.v = b
e.y = l
c.v = j
c.x = b
c.q = m
c.u = m
c.r = f
c.y = i
d.t = j
d.z = j
d.q = n
d.y = n
d.r = b
n.w = b
n.s = b
n.u = c
n.v = l
n.r = e
f.v = j
f.x = b
f.q = m
f.u = m
f.r = m
f.y = i
m.v = j
m.x = l
m.q = f
m.u = f
m.r = c
m.y = i
j.t = d
j.z = d
j.q = n
j.y = n
j.r = b
b.v = j
b.z = j
b.y = i
b.u = l
b.q = m
assert j.r.y.v.v.r.txt == "b"