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

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

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

class D:
    def __init__(self, txt: str):
        self.s: H = None
        self.x: B = None
        self.o: A = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.o: D = None
        self.y: F = None
        self.txt = txt

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

l.t = j
j.v = n
j.x = d
j.t = d
e.p = l
m.s = k
m.x = j
m.o = l
n.w = k
n.t = c
n.v = d
n.s = l
d.r = k
i.y = m
i.x = m
k.y = l
k.x = l
k.v = l
k.q = l
k.w = j
k.s = c
c.v = j
c.o = m
c.y = d
assert d.r.x.t.v.w.w.txt == "
class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.s: H = None
        self.x: B = None
        self.o: A = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.o: D = None
        self.y: F = None
        self.txt = txt

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

l.t = j
j.v = n
j.x = d
j.t = d
e.p = l
m.s = k
m.x = j
m.o = l
n.w = k
n.t = c
n.v = d
n.s = l
d.r = k
i.y = m
i.x = m
k.y = l
k.x = l
k.v = l
k.q = l
k.w = j
k.s = c
c.v = j
c.o = m
c.y = d
assert d.r.x.t.v.w.w.txt == "j"