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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.u: F = None
        self.v: F = None
        self.txt = txt

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

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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.u: F = None
        self.v: F = None
        self.txt = txt

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

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