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

class B:
    def __init__(self, txt: str):
        self.v: A = None
        self.w: H = None
        self.z: G = None
        self.p: I = None
        self.t: I = None
        self.s: G = None
        self.x: F = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: D = None
        self.w: H = None
        self.r: G = None
        self.q: E = None
        self.s: D = None
        self.o: F = None
        self.t: D = None
        self.z: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.t: B = None
        self.v: D = None
        self.u: B = None
        self.p: B = None
        self.r: G = None
        self.x: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.x: A = None
        self.q: H = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: A = None
        self.w: H = None
        self.z: G = None
        self.p: I = None
        self.t: I = None
        self.s: G = None
        self.x: F = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: D = None
        self.w: H = None
        self.r: G = None
        self.q: E = None
        self.s: D = None
        self.o: F = None
        self.t: D = None
        self.z: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.t: B = None
        self.v: D = None
        self.u: B = None
        self.p: B = None
        self.r: G = None
        self.x: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.x: A = None
        self.q: H = None
        self.txt = txt

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

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

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

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