class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.u: J = None
        self.w: C = None
        self.q: F = None
        self.t: D = None
        self.z: E = None
        self.txt = txt

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.r: F = None
        self.q: F = None
        self.o: A = None
        self.w: G = None
        self.u: F = None
        self.txt = txt

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

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

j = A("j")
l = B("l")
a = C("a")
h = D("h")
d = E("d")
m = F("m")
g = G("g")
b = H("b")
c = I("c")
n = J("n")

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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.r: F = None
        self.q: F = None
        self.o: A = None
        self.w: G = None
        self.u: F = None
        self.txt = txt

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

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

j = A("j")
l = B("l")
a = C("a")
h = D("h")
d = E("d")
m = F("m")
g = G("g")
b = H("b")
c = I("c")
n = J("n")

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