class A:
    def __init__(self, txt: str):
        self.w: F = None
        self.y: I = None
        self.t: F = None
        self.x: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: B = None
        self.p: D = None
        self.w: D = None
        self.s: H = None
        self.t: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: F = None
        self.p: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.y: C = None
        self.x: G = None
        self.v: D = None
        self.z: B = None
        self.p: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: E = None
        self.s: G = None
        self.q: H = None
        self.z: I = None
        self.p: I = None
        self.u: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: A = None
        self.z: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: B = None
        self.p: D = None
        self.w: D = None
        self.s: H = None
        self.t: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: F = None
        self.p: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.y: C = None
        self.x: G = None
        self.v: D = None
        self.z: B = None
        self.p: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: E = None
        self.s: G = None
        self.q: H = None
        self.z: I = None
        self.p: I = None
        self.u: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: A = None
        self.z: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.txt = txt

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

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