class A:
    def __init__(self, txt: str):
        self.r: D = None
        self.w: I = None
        self.z: H = None
        self.x: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: G = None
        self.y: A = None
        self.v: G = None
        self.txt = txt

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

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

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

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

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

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

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

class J:
    def __init__(self, txt: str):
        self.q: C = None
        self.r: F = None
        self.o: B = None
        self.v: H = None
        self.z: F = None
        self.y: E = None
        self.u: H = None
        self.w: E = None
        self.t: H = None
        self.p: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: G = None
        self.y: A = None
        self.v: G = None
        self.txt = txt

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

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

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

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

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

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

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

class J:
    def __init__(self, txt: str):
        self.q: C = None
        self.r: F = None
        self.o: B = None
        self.v: H = None
        self.z: F = None
        self.y: E = None
        self.u: H = None
        self.w: E = None
        self.t: H = None
        self.p: C = None
        self.txt = txt

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

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