class A:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: C = None
        self.s: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: A = None
        self.t: C = None
        self.v: D = None
        self.w: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.x: B = None
        self.r: E = None
        self.w: B = None
        self.q: F = None
        self.v: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: D = None
        self.s: E = None
        self.u: C = None
        self.x: F = None
        self.p: G = None
        self.t: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: G = None
        self.y: A = None
        self.t: F = None
        self.q: A = None
        self.r: C = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: A = None
        self.t: C = None
        self.v: D = None
        self.w: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.x: B = None
        self.r: E = None
        self.w: B = None
        self.q: F = None
        self.v: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: D = None
        self.s: E = None
        self.u: C = None
        self.x: F = None
        self.p: G = None
        self.t: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: G = None
        self.y: A = None
        self.t: F = None
        self.q: A = None
        self.r: C = None
        self.txt = txt

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

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

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

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