class A:
    def __init__(self, txt: str):
        self.y: G = None
        self.t: D = None
        self.s: B = None
        self.z: B = None
        self.x: E = None
        self.u: E = None
        self.p: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: A = None
        self.o: F = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.r: C = None
        self.q: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: A = None
        self.o: F = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.r: C = None
        self.q: A = None
        self.txt = txt

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

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