class A:
    def __init__(self, txt: str):
        self.z: C = None
        self.v: I = None
        self.r: D = None
        self.q: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: G = None
        self.o: A = None
        self.s: A = None
        self.w: A = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.t: G = None
        self.q: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: E = None
        self.w: I = None
        self.q: E = None
        self.x: I = None
        self.z: C = None
        self.o: F = None
        self.v: B = None
        self.t: E = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: G = None
        self.o: A = None
        self.s: A = None
        self.w: A = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.t: G = None
        self.q: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: E = None
        self.w: I = None
        self.q: E = None
        self.x: I = None
        self.z: C = None
        self.o: F = None
        self.v: B = None
        self.t: E = None
        self.txt = txt

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

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

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

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