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

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

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.s: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.v: H = None
        self.t: I = None
        self.z: C = None
        self.o: C = None
        self.w: B = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.z: E = None
        self.v: D = None
        self.w: E = None
        self.r: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: C = None
        self.o: E = None
        self.p: B = None
        self.y: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.s: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.v: H = None
        self.t: I = None
        self.z: C = None
        self.o: C = None
        self.w: B = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.z: E = None
        self.v: D = None
        self.w: E = None
        self.r: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: C = None
        self.o: E = None
        self.p: B = None
        self.y: F = None
        self.txt = txt

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

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