class A:
    def __init__(self, txt: str):
        self.s: G = None
        self.u: B = None
        self.t: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.t: G = None
        self.r: G = None
        self.o: D = None
        self.q: B = None
        self.z: F = None
        self.v: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: B = None
        self.p: C = None
        self.t: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.p: B = None
        self.x: A = None
        self.txt = txt

c = A("c")
i = B("i")
j = C("j")
m = D("m")
l = E("l")
n = F("n")
a = G("a")
f = D("f")
d = B("d")
g = B("g")

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: G = None
        self.r: G = None
        self.o: D = None
        self.q: B = None
        self.z: F = None
        self.v: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.z: B = None
        self.p: C = None
        self.t: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.p: B = None
        self.x: A = None
        self.txt = txt

c = A("c")
i = B("i")
j = C("j")
m = D("m")
l = E("l")
n = F("n")
a = G("a")
f = D("f")
d = B("d")
g = B("g")

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