class A:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: G = None
        self.u: I = None
        self.s: G = None
        self.v: E = None
        self.o: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.t: A = None
        self.q: I = None
        self.y: F = None
        self.x: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: B = None
        self.s: H = None
        self.z: F = None
        self.x: B = None
        self.w: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.o: H = None
        self.s: D = None
        self.t: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: D = None
        self.t: G = None
        self.s: G = None
        self.u: B = None
        self.y: G = None
        self.o: D = None
        self.x: D = None
        self.z: D = None
        self.txt = txt

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

a.t = j
a.x = j
a.s = j
a.u = n
a.v = c
a.o = l
f.y = n
f.q = k
b.t = a
b.q = n
b.y = g
b.x = l
k.w = l
k.z = a
k.p = j
c.q = n
m.t = f
m.x = f
m.w = f
m.s = l
m.z = g
j.o = l
j.t = l
j.s = k
l.y = f
n.v = k
n.o = k
n.x = k
n.z = k
n.t = j
n.s = j
n.y = j
n.u = f
g.t = f
g.x = f
g.w = f
g.s = l
g.z = m
assert n.t.o.y.txt == "
class A:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: G = None
        self.u: I = None
        self.s: G = None
        self.v: E = None
        self.o: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.t: A = None
        self.q: I = None
        self.y: F = None
        self.x: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: B = None
        self.s: H = None
        self.z: F = None
        self.x: B = None
        self.w: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.o: H = None
        self.s: D = None
        self.t: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: D = None
        self.t: G = None
        self.s: G = None
        self.u: B = None
        self.y: G = None
        self.o: D = None
        self.x: D = None
        self.z: D = None
        self.txt = txt

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

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