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

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

class C:
    def __init__(self, txt: str):
        self.x: J = None
        self.v: E = None
        self.u: A = None
        self.z: I = None
        self.q: E = None
        self.r: F = None
        self.y: B = None
        self.w: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: J = None
        self.o: I = None
        self.v: H = None
        self.q: F = None
        self.r: A = None
        self.u: H = None
        self.s: B = None
        self.p: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: J = None
        self.z: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: I = None
        self.q: E = None
        self.u: J = None
        self.z: D = None
        self.w: E = None
        self.t: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: I = None
        self.t: E = None
        self.y: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: G = None
        self.v: G = None
        self.t: H = None
        self.w: G = None
        self.o: F = None
        self.s: J = None
        self.z: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.r: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: J = None
        self.v: E = None
        self.u: A = None
        self.z: I = None
        self.q: E = None
        self.r: F = None
        self.y: B = None
        self.w: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: J = None
        self.o: I = None
        self.v: H = None
        self.q: F = None
        self.r: A = None
        self.u: H = None
        self.s: B = None
        self.p: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: J = None
        self.z: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: I = None
        self.q: E = None
        self.u: J = None
        self.z: D = None
        self.w: E = None
        self.t: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: I = None
        self.t: E = None
        self.y: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: G = None
        self.v: G = None
        self.t: H = None
        self.w: G = None
        self.o: F = None
        self.s: J = None
        self.z: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.r: B = None
        self.txt = txt

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

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