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

class B:
    def __init__(self, txt: str):
        self.w: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.s: D = None
        self.r: H = None
        self.w: E = None
        self.u: E = None
        self.x: B = None
        self.p: B = None
        self.v: B = None
        self.q: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.t: I = None
        self.r: E = None
        self.u: G = None
        self.x: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.v: I = None
        self.p: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.q: A = None
        self.x: D = None
        self.p: F = None
        self.s: I = None
        self.y: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: F = None
        self.p: I = None
        self.z: I = None
        self.o: H = None
        self.t: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: B = None
        self.o: F = None
        self.w: A = None
        self.y: C = None
        self.p: F = None
        self.x: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.w: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.s: D = None
        self.r: H = None
        self.w: E = None
        self.u: E = None
        self.x: B = None
        self.p: B = None
        self.v: B = None
        self.q: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.t: I = None
        self.r: E = None
        self.u: G = None
        self.x: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.v: I = None
        self.p: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.q: A = None
        self.x: D = None
        self.p: F = None
        self.s: I = None
        self.y: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: F = None
        self.p: I = None
        self.z: I = None
        self.o: H = None
        self.t: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: B = None
        self.o: F = None
        self.w: A = None
        self.y: C = None
        self.p: F = None
        self.x: B = None
        self.txt = txt

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

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