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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.r: A = None
        self.y: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.y: A = None
        self.z: F = None
        self.w: C = None
        self.x: C = None
        self.txt = txt

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

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

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

c.t = b
c.s = b
c.x = d
c.w = g
h.v = a
h.r = c
h.y = i
f.r = b
f.x = l
f.s = g
f.o = g
i.x = h
k.o = g
k.y = c
k.z = a
k.w = f
k.x = f
l.x = f
l.t = h
l.s = c
g.z = i
g.t = c
g.w = c
g.v = d
g.q = a
g.o = l
a.x = f
a.t = h
a.s = c
b.z = i
b.t = c
b.w = c
b.v = d
b.q = l
b.o = l
d.o = g
d.y = c
d.z = l
d.w = f
d.x = f
assert f.s.o.x.x.t.y.x.r.txt == "
class A:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: E = None
        self.w: G = None
        self.s: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.r: A = None
        self.y: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.y: A = None
        self.z: F = None
        self.w: C = None
        self.x: C = None
        self.txt = txt

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

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

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

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