class A:
    def __init__(self, txt: str):
        self.t: C = None
        self.v: G = None
        self.r: E = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: A = None
        self.y: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: H = None
        self.w: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: F = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: A = None
        self.v: E = None
        self.p: A = None
        self.x: E = None
        self.q: F = None
        self.u: F = None
        self.z: F = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: A = None
        self.y: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: H = None
        self.w: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: F = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: A = None
        self.v: E = None
        self.p: A = None
        self.x: E = None
        self.q: F = None
        self.u: F = None
        self.z: F = None
        self.txt = txt

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

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