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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.t: G = None
        self.w: D = None
        self.u: G = None
        self.s: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: G = None
        self.u: A = None
        self.s: E = None
        self.o: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.q: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: B = None
        self.u: E = None
        self.s: A = None
        self.o: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.t: G = None
        self.w: D = None
        self.u: G = None
        self.s: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: G = None
        self.u: A = None
        self.s: E = None
        self.o: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.q: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: B = None
        self.u: E = None
        self.s: A = None
        self.o: A = None
        self.txt = txt

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

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