class A:
    def __init__(self, txt: str):
        self.z: D = None
        self.o: G = None
        self.s: F = None
        self.x: A = None
        self.p: D = None
        self.q: D = None
        self.txt = txt

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.w: D = None
        self.r: A = None
        self.y: D = None
        self.u: C = None
        self.p: B = None
        self.v: B = None
        self.txt = txt

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

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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.w: D = None
        self.r: A = None
        self.y: D = None
        self.u: C = None
        self.p: B = None
        self.v: B = None
        self.txt = txt

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

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