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

class B:
    def __init__(self, txt: str):
        self.w: H = None
        self.t: G = None
        self.s: I = None
        self.y: G = None
        self.u: G = None
        self.o: I = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.v: J = None
        self.p: C = None
        self.q: D = None
        self.u: B = None
        self.s: E = None
        self.o: A = None
        self.t: H = None
        self.w: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.r: I = None
        self.y: H = None
        self.o: H = None
        self.z: F = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.r: C = None
        self.q: A = None
        self.p: H = None
        self.v: H = None
        self.x: A = None
        self.t: C = None
        self.s: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.w: H = None
        self.t: G = None
        self.s: I = None
        self.y: G = None
        self.u: G = None
        self.o: I = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.v: J = None
        self.p: C = None
        self.q: D = None
        self.u: B = None
        self.s: E = None
        self.o: A = None
        self.t: H = None
        self.w: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.r: I = None
        self.y: H = None
        self.o: H = None
        self.z: F = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.r: C = None
        self.q: A = None
        self.p: H = None
        self.v: H = None
        self.x: A = None
        self.t: C = None
        self.s: A = None
        self.txt = txt

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

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