class A:
    def __init__(self, txt: str):
        self.o: B = None
        self.q: G = None
        self.t: C = None
        self.s: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.z: D = None
        self.t: D = None
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: F = None
        self.x: G = None
        self.y: G = None
        self.p: B = None
        self.r: B = None
        self.v: B = None
        self.q: F = None
        self.o: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: G = None
        self.w: A = None
        self.x: H = None
        self.s: B = None
        self.u: I = None
        self.o: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.u: A = None
        self.w: B = None
        self.v: B = None
        self.p: H = None
        self.s: G = None
        self.r: B = None
        self.x: I = None
        self.z: I = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.q: E = None
        self.t: G = None
        self.s: E = None
        self.x: D = None
        self.p: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: A = None
        self.x: B = None
        self.y: B = None
        self.s: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.z: D = None
        self.t: D = None
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: F = None
        self.x: G = None
        self.y: G = None
        self.p: B = None
        self.r: B = None
        self.v: B = None
        self.q: F = None
        self.o: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: G = None
        self.w: A = None
        self.x: H = None
        self.s: B = None
        self.u: I = None
        self.o: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.u: A = None
        self.w: B = None
        self.v: B = None
        self.p: H = None
        self.s: G = None
        self.r: B = None
        self.x: I = None
        self.z: I = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.q: E = None
        self.t: G = None
        self.s: E = None
        self.x: D = None
        self.p: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: A = None
        self.x: B = None
        self.y: B = None
        self.s: G = None
        self.txt = txt

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

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