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

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

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

class D:
    def __init__(self, txt: str):
        self.t: F = None
        self.o: E = None
        self.z: B = None
        self.s: B = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.z: E = None
        self.o: I = None
        self.v: A = None
        self.y: D = None
        self.s: I = None
        self.q: H = None
        self.r: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.t: B = None
        self.w: F = None
        self.u: G = None
        self.p: E = None
        self.x: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: E = None
        self.q: H = None
        self.y: G = None
        self.txt = txt

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

k.p = c
k.u = c
k.y = n
k.s = n
k.z = n
k.o = i
k.r = i
k.x = e
i.q = e
i.x = f
m.s = e
m.w = e
m.x = k
m.y = l
m.t = j
m.r = i
m.p = n
m.q = f
c.t = j
c.o = n
c.z = i
c.s = i
n.q = j
n.z = f
n.p = f
n.s = m
n.r = e
n.y = i
n.v = i
n.w = k
j.p = e
j.o = n
j.x = n
j.s = n
j.z = n
j.u = n
j.r = c
j.t = c
j.v = f
l.z = n
l.o = e
l.s = e
l.v = k
l.y = c
l.r = c
l.q = f
f.o = k
f.t = i
f.w = j
f.u = l
f.p = n
f.x = n
e.v = n
e.q = f
e.y = l
assert c.o.p.w.t.t.v.p.y.txt == "
class A:
    def __init__(self, txt: str):
        self.p: D = None
        self.y: E = None
        self.o: B = None
        self.x: I = None
        self.r: B = None
        self.s: E = None
        self.z: E = None
        self.u: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.t: F = None
        self.o: E = None
        self.z: B = None
        self.s: B = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.z: E = None
        self.o: I = None
        self.v: A = None
        self.y: D = None
        self.s: I = None
        self.q: H = None
        self.r: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.t: B = None
        self.w: F = None
        self.u: G = None
        self.p: E = None
        self.x: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: E = None
        self.q: H = None
        self.y: G = None
        self.txt = txt

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

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