class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.w: D = None
        self.p: D = None
        self.v: F = None
        self.x: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.t: A = None
        self.s: F = None
        self.r: A = None
        self.w: D = None
        self.z: D = None
        self.p: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.z: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.q: B = None
        self.u: D = None
        self.x: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: C = None
        self.u: F = None
        self.r: E = None
        self.z: E = None
        self.q: C = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.t: A = None
        self.s: F = None
        self.r: A = None
        self.w: D = None
        self.z: D = None
        self.p: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.z: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.q: B = None
        self.u: D = None
        self.x: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: C = None
        self.u: F = None
        self.r: E = None
        self.z: E = None
        self.q: C = None
        self.txt = txt

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

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