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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.r: C = None
        self.txt = txt

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

i = A("i")
h = B("h")
j = C("j")
a = D("a")
c = E("c")
l = F("l")
b = G("b")
n = H("n")
g = I("g")

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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.r: C = None
        self.txt = txt

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

i = A("i")
h = B("h")
j = C("j")
a = D("a")
c = E("c")
l = F("l")
b = G("b")
n = H("n")
g = I("g")

i.z = g
i.o = h
i.v = c
h.t = l
h.v = b
j.t = g
j.q = g
j.y = g
a.r = j
a.t = g
a.o = g
a.u = b
c.x = b
c.w = h
c.o = h
c.q = a
c.v = a
c.s = a
c.u = g
c.t = g
l.y = n
l.r = h
b.x = c
b.y = c
b.v = l
n.r = j
g.y = j
g.p = h
g.o = h
assert n.r.q.p.v.y.t.y.q.txt == "g"