class A:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: C = None
        self.v: E = None
        self.p: F = None
        self.s: B = None
        self.t: D = None
        self.x: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.z: B = None
        self.x: A = None
        self.y: G = None
        self.w: A = None
        self.r: G = None
        self.u: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: B = None
        self.q: E = None
        self.r: D = None
        self.v: D = None
        self.y: D = None
        self.w: E = None
        self.u: G = None
        self.txt = txt

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

c = A("c")
f = B("f")
i = C("i")
h = D("h")
b = E("b")
m = F("m")
g = G("g")
n = F("n")
k = E("k")

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

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

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.z: B = None
        self.x: A = None
        self.y: G = None
        self.w: A = None
        self.r: G = None
        self.u: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: B = None
        self.q: E = None
        self.r: D = None
        self.v: D = None
        self.y: D = None
        self.w: E = None
        self.u: G = None
        self.txt = txt

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

c = A("c")
f = B("f")
i = C("i")
h = D("h")
b = E("b")
m = F("m")
g = G("g")
n = F("n")
k = E("k")

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