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

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

class C:
    def __init__(self, txt: str):
        self.o: A = None
        self.s: F = None
        self.q: I = None
        self.w: E = None
        self.v: A = None
        self.u: I = None
        self.y: A = None
        self.p: D = None
        self.t: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: G = None
        self.u: I = None
        self.q: C = None
        self.w: A = None
        self.s: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.o: H = None
        self.t: F = None
        self.v: E = None
        self.r: D = None
        self.u: A = None
        self.z: D = None
        self.w: C = None
        self.x: C = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.o: A = None
        self.s: F = None
        self.q: I = None
        self.w: E = None
        self.v: A = None
        self.u: I = None
        self.y: A = None
        self.p: D = None
        self.t: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: G = None
        self.u: I = None
        self.q: C = None
        self.w: A = None
        self.s: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.o: H = None
        self.t: F = None
        self.v: E = None
        self.r: D = None
        self.u: A = None
        self.z: D = None
        self.w: C = None
        self.x: C = None
        self.txt = txt

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

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