class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.y: I = None
        self.q: C = None
        self.s: H = None
        self.r: H = None
        self.o: C = None
        self.p: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.u: H = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: C = None
        self.r: E = None
        self.p: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.s: I = None
        self.v: I = None
        self.p: H = None
        self.o: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.w: E = None
        self.t: I = None
        self.o: C = None
        self.s: E = None
        self.v: G = None
        self.z: E = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.u: H = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: C = None
        self.r: E = None
        self.p: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.s: I = None
        self.v: I = None
        self.p: H = None
        self.o: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.w: E = None
        self.t: I = None
        self.o: C = None
        self.s: E = None
        self.v: G = None
        self.z: E = None
        self.txt = txt

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

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

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