class A:
    def __init__(self, txt: str):
        self.s: B = None
        self.y: B = None
        self.u: F = None
        self.z: C = None
        self.o: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.u: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: G = None
        self.t: A = None
        self.z: A = None
        self.q: B = None
        self.s: A = None
        self.p: E = None
        self.u: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: A = None
        self.r: A = None
        self.p: C = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: G = None
        self.t: A = None
        self.z: A = None
        self.q: B = None
        self.s: A = None
        self.p: E = None
        self.u: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: A = None
        self.r: A = None
        self.p: C = None
        self.txt = txt

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

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

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

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