read s
s=c$s
(
  while echo $s | grep -q c; do
    s=$(echo $s | sed s/^[^c]*c//)
    echo $s | sed -nE 's/[^c]*(c[^w]*w[^w]*w).*/\1/p' | wc -c | dc -e?1000+1001%p
  done
) | sort -n | head -1 | sed s/1000/-1/