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

class B:
    def __init__(self, txt: str):
        self.p: A = None
        self.r: C = None
        self.q: C = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: F = None
        self.r: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: G = None
        self.r: A = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: A = None
        self.p: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.p: A = None
        self.r: C = None
        self.q: C = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: F = None
        self.r: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: G = None
        self.r: A = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: A = None
        self.p: D = None
        self.txt = txt

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

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

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