class A:
    def __init__(self, txt: str):
        self.o: E = None
        self.t: C = None
        self.y: C = None
        self.z: G = None
        self.v: J = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.y: I = None
        self.u: D = None
        self.x: J = None
        self.o: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.y: I = None
        self.v: G = None
        self.p: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: A = None
        self.x: H = None
        self.v: E = None
        self.u: G = None
        self.t: J = None
        self.o: C = None
        self.w: B = None
        self.z: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.y: I = None
        self.r: D = None
        self.o: G = None
        self.u: E = None
        self.p: E = None
        self.txt = txt

g = A("g")
l = B("l")
f = C("f")
e = D("e")
i = E("i")
a = F("a")
j = G("j")
b = H("b")
k = I("k")
d = J("d")

g.o = i
g.t = f
g.y = f
g.z = j
g.v = d
l.o = f
l.x = e
l.p = k
f.y = k
f.u = e
f.x = d
f.o = i
e.r = j
i.x = f
i.w = e
a.u = g
j.r = a
j.p = l
b.y = k
b.v = j
b.p = a
k.r = g
k.x = b
k.v = i
k.u = j
k.z = j
k.t = d
k.o = f
k.w = l
d.y = k
d.r = e
d.o = j
d.u = i
d.p = i
assert d.o.r.u.o.txt == "
class A:
    def __init__(self, txt: str):
        self.o: E = None
        self.t: C = None
        self.y: C = None
        self.z: G = None
        self.v: J = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.y: I = None
        self.u: D = None
        self.x: J = None
        self.o: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.y: I = None
        self.v: G = None
        self.p: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: A = None
        self.x: H = None
        self.v: E = None
        self.u: G = None
        self.t: J = None
        self.o: C = None
        self.w: B = None
        self.z: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.y: I = None
        self.r: D = None
        self.o: G = None
        self.u: E = None
        self.p: E = None
        self.txt = txt

g = A("g")
l = B("l")
f = C("f")
e = D("e")
i = E("i")
a = F("a")
j = G("j")
b = H("b")
k = I("k")
d = J("d")

g.o = i
g.t = f
g.y = f
g.z = j
g.v = d
l.o = f
l.x = e
l.p = k
f.y = k
f.u = e
f.x = d
f.o = i
e.r = j
i.x = f
i.w = e
a.u = g
j.r = a
j.p = l
b.y = k
b.v = j
b.p = a
k.r = g
k.x = b
k.v = i
k.u = j
k.z = j
k.t = d
k.o = f
k.w = l
d.y = k
d.r = e
d.o = j
d.u = i
d.p = i
assert d.o.r.u.o.txt == "i"