#![allow(non_snake_case, unused)]
use std::cmp::*;
use std::collections::*;
use std::f64::consts::*;

macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };

    ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, [ $t:tt ]) => {
        {
            let len = read_value!($next, usize);
            (0..len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
        }
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, bytes) => {
        read_value!($next, String).into_bytes()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

fn main() {
    input! {
        n: usize,
        s: chars,
    }
    let mut pattern = vec![('S', 'S'), ('S', 'W'), ('W', 'S'), ('W', 'W')];

    for (f_, s_) in pattern {
        let mut circle = vec!['a'; n + 1];
        circle[0] = f_;
        circle[1] = s_;
        for i in 1..n {
            circle[i + 1] = match (circle[i - 1], circle[i], s[i]) {
                ('S', 'S', 'o') => 'S',
                ('S', 'S', 'x') => 'W',
                ('S', 'W', 'o') => 'W',
                ('S', 'W', 'x') => 'S',
                ('W', 'S', 'o') => 'W',
                ('W', 'S', 'x') => 'S',
                ('W', 'W', 'o') => 'S',
                ('W', 'W', 'x') => 'W',
                (_, _, _) => panic!(),
            }
        }
        if circle[0] == circle[n] {
            let acc = match (circle[n - 1], circle[0], circle[1]) {
                ('S', 'S', 'S') => 'o',
                ('S', 'S', 'W') => 'x',
                ('S', 'W', 'S') => 'x',
                ('S', 'W', 'W') => 'o',
                ('W', 'S', 'S') => 'x',
                ('W', 'S', 'W') => 'o',
                ('W', 'W', 'S') => 'o',
                ('W', 'W', 'W') => 'x',
                (_, _, _) => panic!(),
            };
            if acc == s[0] {
                return println!(
                    "{}",
                    circle[..n]
                        .iter()
                        .fold(String::new(), |acc, s| acc + &s.to_string())
                );
            }
        }
    }
    println!("-1");
}


Measured memory_bytes: 4352