class A:
    def __init__(self, txt: str):
        self.w: D = None
        self.q: C = None
        self.z: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: C = None
        self.x: D = None
        self.q: D = None
        self.r: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.p: G = None
        self.x: F = None
        self.v: F = None
        self.y: G = None
        self.q: D = None
        self.o: G = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.o: C = None
        self.x: D = None
        self.q: D = None
        self.r: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.p: G = None
        self.x: F = None
        self.v: F = None
        self.y: G = None
        self.q: D = None
        self.o: G = None
        self.txt = txt

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

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

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

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