class A:
    def __init__(self, txt: str):
        self.z: A = None
        self.t: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.q: F = None
        self.u: C = None
        self.o: C = None
        self.y: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: F = None
        self.y: F = None
        self.t: C = None
        self.s: F = None
        self.v: A = None
        self.txt = txt

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

j = A("j")
c = B("c")
n = C("n")
g = D("g")
f = E("f")
i = F("i")
k = A("k")
d = C("d")
e = D("e")
l = E("l")

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

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

class C:
    def __init__(self, txt: str):
        self.q: F = None
        self.u: C = None
        self.o: C = None
        self.y: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: F = None
        self.y: F = None
        self.t: C = None
        self.s: F = None
        self.v: A = None
        self.txt = txt

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

j = A("j")
c = B("c")
n = C("n")
g = D("g")
f = E("f")
i = F("i")
k = A("k")
d = C("d")
e = D("e")
l = E("l")

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