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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.s: C = None
        self.x: A = None
        self.v: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: H = None
        self.t: C = None
        self.y: I = None
        self.q: C = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.v: G = None
        self.x: E = None
        self.r: A = None
        self.p: B = None
        self.u: D = None
        self.w: D = None
        self.z: E = None
        self.o: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: A = None
        self.s: A = None
        self.y: A = None
        self.t: E = None
        self.u: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.s: C = None
        self.x: A = None
        self.v: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: H = None
        self.t: C = None
        self.y: I = None
        self.q: C = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.v: G = None
        self.x: E = None
        self.r: A = None
        self.p: B = None
        self.u: D = None
        self.w: D = None
        self.z: E = None
        self.o: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: A = None
        self.s: A = None
        self.y: A = None
        self.t: E = None
        self.u: F = None
        self.txt = txt

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

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