class A:
    def __init__(self, txt: str):
        self.y: C = None
        self.z: H = None
        self.x: C = None
        self.t: H = None
        self.q: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: C = None
        self.y: A = None
        self.q: C = None
        self.p: G = None
        self.z: I = None
        self.t: C = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.r: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: D = None
        self.w: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: E = None
        self.t: F = None
        self.p: F = None
        self.q: D = None
        self.r: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: E = None
        self.w: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.w: C = None
        self.y: A = None
        self.q: C = None
        self.p: G = None
        self.z: I = None
        self.t: C = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.r: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: D = None
        self.w: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: E = None
        self.t: F = None
        self.p: F = None
        self.q: D = None
        self.r: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: E = None
        self.w: E = None
        self.txt = txt

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

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