class A:
    def __init__(self, txt: str):
        self.o: E = None
        self.v: E = None
        self.q: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.u: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: J = None
        self.w: F = None
        self.o: E = None
        self.t: F = None
        self.y: A = None
        self.z: J = None
        self.p: F = None
        self.r: G = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: F = None
        self.q: H = None
        self.y: H = None
        self.w: B = None
        self.r: A = None
        self.x: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: I = None
        self.w: J = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.q: G = None
        self.p: C = None
        self.txt = txt

k = A("k")
l = B("l")
d = C("d")
c = D("c")
e = E("e")
g = F("g")
m = G("m")
n = H("n")
a = I("a")
i = J("i")

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

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

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.u: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: J = None
        self.w: F = None
        self.o: E = None
        self.t: F = None
        self.y: A = None
        self.z: J = None
        self.p: F = None
        self.r: G = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: F = None
        self.q: H = None
        self.y: H = None
        self.w: B = None
        self.r: A = None
        self.x: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: I = None
        self.w: J = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.q: G = None
        self.p: C = None
        self.txt = txt

k = A("k")
l = B("l")
d = C("d")
c = D("c")
e = E("e")
g = F("g")
m = G("m")
n = H("n")
a = I("a")
i = J("i")

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