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

class B:
    def __init__(self, txt: str):
        self.y: H = None
        self.w: D = None
        self.q: A = None
        self.p: I = None
        self.v: A = None
        self.r: D = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.z: F = None
        self.s: H = None
        self.v: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: F = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: C = None
        self.p: I = None
        self.w: E = None
        self.v: E = None
        self.u: A = None
        self.r: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: B = None
        self.o: F = None
        self.q: H = None
        self.x: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: H = None
        self.w: D = None
        self.q: A = None
        self.p: I = None
        self.v: A = None
        self.r: D = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.z: F = None
        self.s: H = None
        self.v: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: F = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: C = None
        self.p: I = None
        self.w: E = None
        self.v: E = None
        self.u: A = None
        self.r: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: B = None
        self.o: F = None
        self.q: H = None
        self.x: G = None
        self.txt = txt

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

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