class A:
    def __init__(self, txt: str):
        self.y: E = None
        self.x: G = None
        self.q: E = None
        self.s: C = None
        self.u: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: D = None
        self.s: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: F = None
        self.t: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: H = None
        self.o: H = None
        self.p: C = None
        self.u: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.o: F = None
        self.y: J = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.z: G = None
        self.s: E = None
        self.x: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: E = None
        self.txt = txt

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

i = A("i")
f = B("f")
h = C("h")
c = D("c")
n = E("n")
b = F("b")
k = G("k")
g = H("g")
l = I("l")
d = J("d")

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

class B:
    def __init__(self, txt: str):
        self.t: D = None
        self.s: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: F = None
        self.t: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: H = None
        self.o: H = None
        self.p: C = None
        self.u: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.o: F = None
        self.y: J = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.z: G = None
        self.s: E = None
        self.x: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: E = None
        self.txt = txt

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

i = A("i")
f = B("f")
h = C("h")
c = D("c")
n = E("n")
b = F("b")
k = G("k")
g = H("g")
l = I("l")
d = J("d")

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