class A:
    def __init__(self, txt: str):
        self.y: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.w: C = None
        self.t: A = None
        self.o: C = None
        self.r: E = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.v: E = None
        self.o: A = None
        self.q: E = None
        self.u: E = None
        self.z: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: C = None
        self.w: B = None
        self.v: A = None
        self.q: E = None
        self.u: C = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.w: C = None
        self.t: A = None
        self.o: C = None
        self.r: E = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.v: E = None
        self.o: A = None
        self.q: E = None
        self.u: E = None
        self.z: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: C = None
        self.w: B = None
        self.v: A = None
        self.q: E = None
        self.u: C = None
        self.txt = txt

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

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

h.y = e
i.z = e
i.w = f
i.o = f
i.t = h
i.r = l
f.s = d
f.y = d
f.u = e
k.t = e
k.u = e
k.p = e
k.s = n
k.o = l
k.w = h
l.v = e
l.q = e
l.u = e
l.o = h
l.z = i
n.r = f
n.u = f
n.w = g
n.v = h
n.q = l
b.t = g
b.p = f
b.x = h
e.v = l
e.q = l
e.u = l
e.o = h
e.z = g
d.z = l
d.r = l
d.w = f
d.o = f
d.t = h
g.z = e
g.w = f
g.o = f
g.t = h
g.r = l
assert k.t.q.o.y.z.r.z.r.txt == "l"