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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.r: D = None
        self.x: D = None
        self.p: G = None
        self.y: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.v: I = None
        self.p: I = None
        self.z: A = None
        self.r: D = None
        self.u: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.v: A = None
        self.r: I = None
        self.u: A = None
        self.s: I = None
        self.y: D = None
        self.w: G = None
        self.t: E = None
        self.p: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: I = None
        self.u: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: C = None
        self.p: G = None
        self.w: C = None
        self.q: D = None
        self.t: E = None
        self.u: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.r: D = None
        self.x: D = None
        self.p: G = None
        self.y: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.v: I = None
        self.p: I = None
        self.z: A = None
        self.r: D = None
        self.u: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.v: A = None
        self.r: I = None
        self.u: A = None
        self.s: I = None
        self.y: D = None
        self.w: G = None
        self.t: E = None
        self.p: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: I = None
        self.u: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: C = None
        self.p: G = None
        self.w: C = None
        self.q: D = None
        self.t: E = None
        self.u: E = None
        self.txt = txt

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

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