Tour Course

The UCPC Kingdom has a circular tour route made of $N$ segments that together cover the whole kingdom. Each segment has a shuttle bus to the next segment. From segment $i$ with $1\leq i<N$, you can move to segment $i+1$, and from segment $N$ you can move to segment $1$.

Now $N$ tourists from the Arctic will tour the UCPC Kingdom on this route. The $i$-th tourist starts at segment $i$ and rides the shuttle buses to tour $N$ segments in total.

Each segment is either a snowfield or a desert. Every tourist starts at their starting point with an affection of $1$. Each time they pass a snowfield segment, their affection increases by $1$, and each time they pass a desert segment, it decreases by $1$. If the affection reaches $0$ during the tour, the tourist stops immediately and leaves for their home country. After touring all $N$ segments, a tourist whose affection is at least $1$ buys an expensive souvenir from the UCPC Kingdom and returns home.

You live in the Arctic and know which tourists bought a souvenir. Use that information to work out the structure of the tour route. Given the purchase status of tourists 1 through $N$, print one possible structure of the route.

If a route exists for the given input, print YES on the first line and a string of length $N$ on the second line. The $i$-th character is + if segment $i$ is a snowfield and - if it is a desert.

If no route exists, print NO on the first line.

The first line contains $N$ ($1\leq N\leq 500\,000$). The second line contains a string of length $N$. The $i$-th character is O if tourist $i$ bought a souvenir and X if not.