class A:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: I = None
        self.x: C = None
        self.t: E = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: H = None
        self.u: A = None
        self.w: G = None
        self.v: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: I = None
        self.q: E = None
        self.x: C = None
        self.w: I = None
        self.u: I = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: H = None
        self.u: A = None
        self.w: G = None
        self.v: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: I = None
        self.q: E = None
        self.x: C = None
        self.w: I = None
        self.u: I = None
        self.txt = txt

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

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

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