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

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

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.v: A = None
        self.y: C = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.w: I = None
        self.p: I = None
        self.z: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: C = None
        self.y: B = None
        self.o: G = None
        self.z: A = None
        self.u: E = None
        self.p: B = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.y: G = None
        self.z: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.v: A = None
        self.y: C = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.w: I = None
        self.p: I = None
        self.z: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: C = None
        self.y: B = None
        self.o: G = None
        self.z: A = None
        self.u: E = None
        self.p: B = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.y: G = None
        self.z: D = None
        self.txt = txt

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

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