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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.p: B = None
        self.o: C = None
        self.w: F = None
        self.z: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: C = None
        self.y: D = None
        self.q: G = None
        self.x: G = None
        self.r: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: C = None
        self.x: A = None
        self.o: D = None
        self.s: C = None
        self.w: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: H = None
        self.x: C = None
        self.o: E = None
        self.y: C = None
        self.v: F = None
        self.q: F = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.p: B = None
        self.o: C = None
        self.w: F = None
        self.z: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: C = None
        self.y: D = None
        self.q: G = None
        self.x: G = None
        self.r: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: C = None
        self.x: A = None
        self.o: D = None
        self.s: C = None
        self.w: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: H = None
        self.x: C = None
        self.o: E = None
        self.y: C = None
        self.v: F = None
        self.q: F = None
        self.txt = txt

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

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