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

class B:
    def __init__(self, txt: str):
        self.q: C = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.z: B = None
        self.s: F = None
        self.w: D = None
        self.p: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: F = None
        self.s: E = None
        self.p: E = None
        self.v: E = None
        self.y: F = None
        self.u: C = None
        self.txt = txt

l = A("l")
j = B("j")
a = C("a")
e = D("e")
i = E("i")
b = F("b")
c = F("c")

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

class B:
    def __init__(self, txt: str):
        self.q: C = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.z: B = None
        self.s: F = None
        self.w: D = None
        self.p: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: F = None
        self.s: E = None
        self.p: E = None
        self.v: E = None
        self.y: F = None
        self.u: C = None
        self.txt = txt

l = A("l")
j = B("j")
a = C("a")
e = D("e")
i = E("i")
b = F("b")
c = F("c")

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