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

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

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

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

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.y: B = None
        self.w: B = None
        self.s: I = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.y: B = None
        self.w: B = None
        self.s: I = None
        self.txt = txt

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

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

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

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

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

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