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

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

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: G = None
        self.y: F = None
        self.v: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.t: B = None
        self.p: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: G = None
        self.y: F = None
        self.v: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.t: B = None
        self.p: F = None
        self.txt = txt

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

b.o = m
b.u = j
b.t = c
f.t = g
f.v = j
f.y = j
f.q = l
j.w = m
j.s = e
j.y = c
j.v = c
g.y = c
k.p = j
k.s = j
c.y = f
e.s = k
e.t = l
e.p = c
n.p = j
n.s = j
l.t = g
l.v = j
l.y = j
l.q = f
m.o = b
m.u = j
m.t = c
assert j.s.t.q.t.y.y.v.v.txt == "c"