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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.r: F = None
        self.p: G = None
        self.t: H = None
        self.y: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.r: D = None
        self.x: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.o: E = None
        self.q: C = None
        self.w: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.t: B = None
        self.z: C = None
        self.q: D = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.r: F = None
        self.p: G = None
        self.t: H = None
        self.y: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.r: D = None
        self.x: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.u: A = None
        self.o: E = None
        self.q: C = None
        self.w: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.t: B = None
        self.z: C = None
        self.q: D = None
        self.txt = txt

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

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

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

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