class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.r: C = None
        self.s: G = None
        self.y: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.s: G = None
        self.w: D = None
        self.x: A = None
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: H = None
        self.w: G = None
        self.z: E = None
        self.u: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: H = None
        self.u: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: E = None
        self.x: E = None
        self.q: D = None
        self.s: E = None
        self.t: C = None
        self.v: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.p: C = None
        self.q: A = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.s: G = None
        self.w: D = None
        self.x: A = None
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: H = None
        self.w: G = None
        self.z: E = None
        self.u: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: H = None
        self.u: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: E = None
        self.x: E = None
        self.q: D = None
        self.s: E = None
        self.t: C = None
        self.v: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.p: C = None
        self.q: A = None
        self.txt = txt

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

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

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