class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.v: I = None
        self.u: F = None
        self.y: J = None
        self.q: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: C = None
        self.z: A = None
        self.v: E = None
        self.s: A = None
        self.x: C = None
        self.q: J = None
        self.y: F = None
        self.o: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: B = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.z: E = None
        self.r: J = None
        self.t: J = None
        self.y: D = None
        self.p: G = None
        self.v: J = None
        self.x: C = None
        self.txt = txt

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

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

m.s = d
m.v = j
m.u = b
m.y = k
m.q = a
n.t = g
n.x = g
n.z = m
n.s = m
n.v = d
n.q = k
n.y = b
n.o = a
g.z = d
a.v = j
a.o = j
a.q = n
a.p = n
a.z = k
a.u = b
a.s = d
d.y = i
d.p = i
d.s = j
d.t = j
d.x = b
d.q = g
b.p = n
c.s = a
c.v = b
c.o = n
i.x = j
i.p = n
j.z = d
j.r = k
j.t = k
j.v = k
j.y = a
j.p = c
j.x = g
k.o = a
k.x = a
assert i.x.z.x.p.q.x.txt == "
class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.v: I = None
        self.u: F = None
        self.y: J = None
        self.q: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: C = None
        self.z: A = None
        self.v: E = None
        self.s: A = None
        self.x: C = None
        self.q: J = None
        self.y: F = None
        self.o: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: B = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.z: E = None
        self.r: J = None
        self.t: J = None
        self.y: D = None
        self.p: G = None
        self.v: J = None
        self.x: C = None
        self.txt = txt

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

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

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