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

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

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

class D:
    def __init__(self, txt: str):
        self.w: D = None
        self.y: E = None
        self.z: D = None
        self.t: A = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.w: D = None
        self.y: E = None
        self.z: D = None
        self.t: A = None
        self.txt = txt

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

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

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