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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.p: C = None
        self.t: C = None
        self.q: A = None
        self.w: G = None
        self.txt = txt

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

a = A("a")
e = B("e")
m = C("m")
j = D("j")
g = E("g")
i = F("i")
l = G("l")
d = E("d")
b = C("b")

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.p: C = None
        self.t: C = None
        self.q: A = None
        self.w: G = None
        self.txt = txt

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

a = A("a")
e = B("e")
m = C("m")
j = D("j")
g = E("g")
i = F("i")
l = G("l")
d = E("d")
b = C("b")

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