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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: B = None
        self.x: H = None
        self.r: C = None
        self.u: I = None
        self.z: I = None
        self.w: B = None
        self.v: I = None
        self.s: H = None
        self.q: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: I = None
        self.r: F = None
        self.txt = txt

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

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

m = A("m")
g = B("g")
n = C("n")
k = D("k")
f = E("f")
a = F("a")
h = G("h")
e = H("e")
i = I("i")
l = C("l")

m.v = n
m.z = i
g.p = l
n.q = a
n.y = i
n.w = f
k.u = n
k.o = m
f.u = a
f.y = m
f.p = g
f.t = h
a.o = g
a.w = g
a.x = e
a.s = e
a.r = l
a.u = i
a.z = i
a.v = i
a.q = i
h.q = i
h.r = a
e.u = i
e.v = i
e.r = h
i.s = e
i.p = e
l.q = a
l.y = i
l.w = f
assert m.z.p.u.p.v.p.u.p.u.txt == "
class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.z: I = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: B = None
        self.x: H = None
        self.r: C = None
        self.u: I = None
        self.z: I = None
        self.w: B = None
        self.v: I = None
        self.s: H = None
        self.q: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: I = None
        self.r: F = None
        self.txt = txt

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

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

m = A("m")
g = B("g")
n = C("n")
k = D("k")
f = E("f")
a = F("a")
h = G("h")
e = H("e")
i = I("i")
l = C("l")

m.v = n
m.z = i
g.p = l
n.q = a
n.y = i
n.w = f
k.u = n
k.o = m
f.u = a
f.y = m
f.p = g
f.t = h
a.o = g
a.w = g
a.x = e
a.s = e
a.r = l
a.u = i
a.z = i
a.v = i
a.q = i
h.q = i
h.r = a
e.u = i
e.v = i
e.r = h
i.s = e
i.p = e
l.q = a
l.y = i
l.w = f
assert m.z.p.u.p.v.p.u.p.u.txt == "i"