class A:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: E = None
        self.q: F = None
        self.x: G = None
        self.u: E = None
        self.y: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: H = None
        self.o: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.z: I = None
        self.u: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: I = None
        self.v: I = None
        self.o: I = None
        self.u: D = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: H = None
        self.p: E = None
        self.q: A = None
        self.y: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: E = None
        self.x: G = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: H = None
        self.o: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.z: I = None
        self.u: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: I = None
        self.v: I = None
        self.o: I = None
        self.u: D = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: H = None
        self.p: E = None
        self.q: A = None
        self.y: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: E = None
        self.x: G = None
        self.txt = txt

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

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

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