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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.v: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.p: E = None
        self.w: I = None
        self.x: H = None
        self.s: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.q: G = None
        self.o: B = None
        self.z: D = None
        self.x: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.w: E = None
        self.y: H = None
        self.u: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: C = None
        self.u: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: A = None
        self.r: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.v: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.p: E = None
        self.w: I = None
        self.x: H = None
        self.s: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.q: G = None
        self.o: B = None
        self.z: D = None
        self.x: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.w: E = None
        self.y: H = None
        self.u: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: C = None
        self.u: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: A = None
        self.r: E = None
        self.txt = txt

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

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