class A:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: F = None
        self.z: B = None
        self.s: G = None
        self.v: E = None
        self.t: H = None
        self.o: H = None
        self.x: H = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.z: H = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.u: I = None
        self.r: F = None
        self.v: B = None
        self.o: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: G = None
        self.p: D = None
        self.s: A = None
        self.x: H = None
        self.o: B = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.z: H = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.u: I = None
        self.r: F = None
        self.v: B = None
        self.o: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: G = None
        self.p: D = None
        self.s: A = None
        self.x: H = None
        self.o: B = None
        self.txt = txt

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

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