class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: I = None
        self.u: I = None
        self.r: F = None
        self.t: C = None
        self.txt = txt

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.x: J = None
        self.p: I = None
        self.r: D = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.w: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: I = None
        self.u: I = None
        self.r: F = None
        self.t: C = None
        self.txt = txt

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.x: J = None
        self.p: I = None
        self.r: D = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.w: F = None
        self.txt = txt

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

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