class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: H = None
        self.o: A = None
        self.y: A = None
        self.q: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: A = None
        self.y: H = None
        self.t: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: C = None
        self.v: H = None
        self.u: D = None
        self.q: H = None
        self.o: H = None
        self.r: A = None
        self.t: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: A = None
        self.t: D = None
        self.w: I = None
        self.z: I = None
        self.s: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.p: E = None
        self.o: F = None
        self.t: A = None
        self.r: C = None
        self.x: D = None
        self.u: E = None
        self.z: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: H = None
        self.o: A = None
        self.y: A = None
        self.q: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: A = None
        self.y: H = None
        self.t: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: C = None
        self.v: H = None
        self.u: D = None
        self.q: H = None
        self.o: H = None
        self.r: A = None
        self.t: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: A = None
        self.t: D = None
        self.w: I = None
        self.z: I = None
        self.s: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.p: E = None
        self.o: F = None
        self.t: A = None
        self.r: C = None
        self.x: D = None
        self.u: E = None
        self.z: C = None
        self.txt = txt

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

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