class A:
    def __init__(self, txt: str):
        self.o: B = None
        self.s: E = None
        self.u: C = None
        self.r: G = None
        self.v: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.w: G = None
        self.o: D = None
        self.r: H = None
        self.q: A = None
        self.t: I = None
        self.p: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: E = None
        self.p: A = None
        self.q: F = None
        self.r: C = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: B = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.w: G = None
        self.o: D = None
        self.r: H = None
        self.q: A = None
        self.t: I = None
        self.p: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: E = None
        self.p: A = None
        self.q: F = None
        self.r: C = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: B = None
        self.txt = txt

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

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

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