class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.w: A = None
        self.y: E = None
        self.p: B = None
        self.o: G = None
        self.q: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.y: F = None
        self.u: F = None
        self.x: A = None
        self.w: F = None
        self.s: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: E = None
        self.o: A = None
        self.w: G = None
        self.v: B = None
        self.y: B = None
        self.s: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: G = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.o: E = None
        self.y: E = None
        self.v: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.y: F = None
        self.u: F = None
        self.x: A = None
        self.w: F = None
        self.s: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: E = None
        self.o: A = None
        self.w: G = None
        self.v: B = None
        self.y: B = None
        self.s: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: G = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.o: E = None
        self.y: E = None
        self.v: E = None
        self.txt = txt

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

i.t = l
i.q = l
i.w = a
i.y = j
i.p = f
i.o = n
f.v = l
f.y = l
f.u = l
f.w = l
f.x = i
f.s = j
h.p = c
h.o = k
h.w = n
h.v = f
h.y = f
h.s = i
b.q = n
j.u = n
j.x = h
l.r = h
l.q = a
l.w = b
n.s = f
n.o = j
n.y = j
n.v = j
k.t = l
k.q = l
k.w = a
k.y = c
k.p = f
k.o = n
a.t = l
a.q = l
a.w = k
a.y = j
a.p = f
a.o = n
c.u = n
c.x = h
assert k.y.u.s.x.w.o.s.s.x.s.txt == "i"