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

class B:
    def __init__(self, txt: str):
        self.t: A = None
        self.u: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.q: C = None
        self.x: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.x: J = None
        self.p: G = None
        self.s: H = None
        self.y: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: B = None
        self.v: B = None
        self.y: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.w: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: H = None
        self.w: F = None
        self.x: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: A = None
        self.u: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.q: C = None
        self.x: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.x: J = None
        self.p: G = None
        self.s: H = None
        self.y: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: B = None
        self.v: B = None
        self.y: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.w: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: H = None
        self.w: F = None
        self.x: C = None
        self.txt = txt

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

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