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xxxxxx     rrxxxxx
xxxx       frrrxxx
xxxrf h        fxx
xxx  f  f       xx
xx  f            x
xxf       rr     x
xx       rrr     x
xx      frrp    fx
xx               x
xx  f          f x
xx  frrr    f    x
xxx  rrrr       xx
xxx    rrr f    xx
xxxx    rr   rrxxx
xxxxxx  rr   xxxxx
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