class A:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: J = None
        self.v: B = None
        self.y: I = None
        self.t: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.v: A = None
        self.u: I = None
        self.z: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.y: D = None
        self.w: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: G = None
        self.v: E = None
        self.p: D = None
        self.r: B = None
        self.u: D = None
        self.q: D = None
        self.s: I = None
        self.t: I = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.r: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.u: F = None
        self.t: G = None
        self.o: B = None
        self.r: H = None
        self.y: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.v: A = None
        self.u: I = None
        self.z: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.y: D = None
        self.w: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: G = None
        self.v: E = None
        self.p: D = None
        self.r: B = None
        self.u: D = None
        self.q: D = None
        self.s: I = None
        self.t: I = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.r: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.u: F = None
        self.t: G = None
        self.o: B = None
        self.r: H = None
        self.y: H = None
        self.txt = txt

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

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