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

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

class C:
    def __init__(self, txt: str):
        self.r: A = None
        self.w: G = None
        self.txt = txt

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

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

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

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

f = A("f")
a = B("a")
e = C("e")
h = D("h")
b = E("b")
l = F("l")
g = G("g")
k = A("k")
m = E("m")
j = F("j")

f.s = h
f.o = e
f.x = e
f.v = g
f.r = g
f.w = l
a.v = m
a.w = e
a.t = e
a.x = f
e.r = k
e.w = g
h.z = e
h.x = g
b.x = l
b.q = f
b.s = m
b.y = m
b.o = h
b.v = e
l.s = a
l.w = a
l.t = j
l.z = m
g.r = b
k.s = h
k.o = e
k.x = e
k.v = g
k.r = g
k.w = j
m.x = l
m.q = k
m.s = b
m.y = b
m.o = h
m.v = e
j.s = a
j.w = a
j.t = l
j.z = b
assert l.t.t.s.txt == "
class A:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: C = None
        self.v: G = None
        self.x: C = None
        self.w: F = None
        self.r: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: A = None
        self.w: G = None
        self.txt = txt

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

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

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

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

f = A("f")
a = B("a")
e = C("e")
h = D("h")
b = E("b")
l = F("l")
g = G("g")
k = A("k")
m = E("m")
j = F("j")

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