class A:
    def __init__(self, txt: str):
        self.o: I = None
        self.t: B = None
        self.r: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: D = None
        self.y: E = None
        self.z: D = None
        self.u: I = None
        self.q: B = None
        self.v: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: J = None
        self.z: J = None
        self.p: J = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: F = None
        self.v: B = None
        self.y: I = None
        self.q: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.z: B = None
        self.u: E = None
        self.r: H = None
        self.s: F = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: D = None
        self.y: E = None
        self.z: D = None
        self.u: I = None
        self.q: B = None
        self.v: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.v: J = None
        self.z: J = None
        self.p: J = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: F = None
        self.v: B = None
        self.y: I = None
        self.q: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.z: B = None
        self.u: E = None
        self.r: H = None
        self.s: F = None
        self.txt = txt

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

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

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