#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)
#define repp(i,m,n) for(int (i)=(m);(i)<(n);(i)++)
#define repm(i,n) for(int (i)=(n-1);(i)>=0;(i)--)
#define INF (1ll<<60)
#define all(x) (x).begin(),(x).end()
typedef long long lint;
const lint MOD =1000000007;
const lint MAX = 1000000;
using Graph =vector<vector<lint>>;
typedef pair<lint,lint> P;
 
 
lint fac[MAX], finv[MAX], inv[MAX];
 
void COMinit() 
{
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for (lint i = 2; i < MAX; i++)
    {
        fac[i] = fac[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
        finv[i] = finv[i - 1] * inv[i] % MOD;
    }
}
 
long long COM(lint n, lint k)
{
    if (n < k)
        return 0;
    if (n < 0 || k < 0)
        return 0;
    return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
 
lint primary(lint num)
{
    if (num < 2) return 0;
    else if (num == 2) return 1;
    else if (num % 2 == 0) return 0;
 
    double sqrtNum = sqrt(num);
    for (int i = 3; i <= sqrtNum; i += 2)
    {
        if (num % i == 0)
        {
            return 0;
        }
    }
 
    return 1;
}
   long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}
    lint lcm(lint a,lint b){
        return a/__gcd(a,b)*b;
    }
     lint gcd(lint a,lint b){
        return __gcd(a,b);
    } 
    //解説AC
  int main(){
    lint n;
    string s;
    cin>>n>>s;
   vector<char> ans;
   ans.push_back('S');
   ans.push_back('S');
   rep(i,n-2){
       if(ans[i]=='S'&&ans[i+1]=='S'&&s[i+1]=='o')ans.push_back('S');
       if(ans[i]=='S'&&ans[i+1]=='S'&&s[i+1]=='x')ans.push_back('W');
       if(ans[i]=='S'&&ans[i+1]=='W'&&s[i+1]=='o')ans.push_back('W');
       if(ans[i]=='S'&&ans[i+1]=='W'&&s[i+1]=='x')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='S'&&s[i+1]=='o')ans.push_back('W');
       if(ans[i]=='W'&&ans[i+1]=='S'&&s[i+1]=='x')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='W'&&s[i+1]=='o')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='W'&&s[i+1]=='x')ans.push_back('W');
   }
   if(ans[n-1]=='S'){
   if(((s[0]=='o'&&ans[1]==ans[n-1])||(s[0]=='x'&&ans[1]!=ans[n-1]))&&((s[n-1]=='o'&&ans[0]==ans[n-2])||(s[n-1]=='x'&&ans[n-2]!=ans[0]))){
       rep(i,n)cout<<ans[i];
       return 0;
   }
   }
     if(ans[n-1]=='W'){
   if(((s[0]=='o'&&ans[1]==ans[n-1])||(s[0]=='x'&&ans[1]!=ans[n-1]))&&((s[n-1]=='o'&&ans[0]!=ans[n-2])||(s[n-1]=='x'&&ans[n-2]==ans[0]))){
       rep(i,n)cout<<ans[i];
       return 0;
   }
   }
   ans.resize(0);
    ans.push_back('S');
   ans.push_back('W');
   rep(i,n-2){
       if(ans[i]=='S'&&ans[i+1]=='S'&&s[i+1]=='o')ans.push_back('S');
       if(ans[i]=='S'&&ans[i+1]=='S'&&s[i+1]=='x')ans.push_back('W');
       if(ans[i]=='S'&&ans[i+1]=='W'&&s[i+1]=='o')ans.push_back('W');
       if(ans[i]=='S'&&ans[i+1]=='W'&&s[i+1]=='x')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='S'&&s[i+1]=='o')ans.push_back('W');
       if(ans[i]=='W'&&ans[i+1]=='S'&&s[i+1]=='x')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='W'&&s[i+1]=='o')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='W'&&s[i+1]=='x')ans.push_back('W');
   }
   if(ans[n-1]=='S'){
   if(((s[0]=='o'&&ans[1]==ans[n-1])||(s[0]=='x'&&ans[1]!=ans[n-1]))&&((s[n-1]=='o'&&ans[0]==ans[n-2])||(s[n-1]=='x'&&ans[n-2]!=ans[0]))){
       rep(i,n)cout<<ans[i];
       return 0;
   }
   }
     if(ans[n-1]=='W'){
   if(((s[0]=='o'&&ans[1]==ans[n-1])||(s[0]=='x'&&ans[1]!=ans[n-1]))&&((s[n-1]=='o'&&ans[0]!=ans[n-2])||(s[n-1]=='x'&&ans[n-2]==ans[0]))){
       rep(i,n)cout<<ans[i];
       return 0;
   }
   }
   ans.resize(0);
    ans.push_back('W');
   ans.push_back('S');
   rep(i,n-2){
       if(ans[i]=='S'&&ans[i+1]=='S'&&s[i+1]=='o')ans.push_back('S');
       if(ans[i]=='S'&&ans[i+1]=='S'&&s[i+1]=='x')ans.push_back('W');
       if(ans[i]=='S'&&ans[i+1]=='W'&&s[i+1]=='o')ans.push_back('W');
       if(ans[i]=='S'&&ans[i+1]=='W'&&s[i+1]=='x')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='S'&&s[i+1]=='o')ans.push_back('W');
       if(ans[i]=='W'&&ans[i+1]=='S'&&s[i+1]=='x')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='W'&&s[i+1]=='o')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='W'&&s[i+1]=='x')ans.push_back('W');
   }
 if(ans[n-1]=='S'){
   if(((s[0]=='o'&&ans[1]!=ans[n-1])||(s[0]=='x'&&ans[1]==ans[n-1]))&&((s[n-1]=='o'&&ans[0]==ans[n-2])||(s[n-1]=='x'&&ans[n-2]!=ans[0]))){
       rep(i,n)cout<<ans[i];
       return 0;
   }
   }
     if(ans[n-1]=='W'){
   if(((s[0]=='o'&&ans[1]!=ans[n-1])||(s[0]=='x'&&ans[1]==ans[n-1]))&&((s[n-1]=='o'&&ans[0]!=ans[n-2])||(s[n-1]=='x'&&ans[n-2]==ans[0]))){
       rep(i,n)cout<<ans[i];
       return 0;
   }
   }
   ans.resize(0);
    ans.push_back('W');
   ans.push_back('W');
   rep(i,n-2){
       if(ans[i]=='S'&&ans[i+1]=='S'&&s[i+1]=='o')ans.push_back('S');
       if(ans[i]=='S'&&ans[i+1]=='S'&&s[i+1]=='x')ans.push_back('W');
       if(ans[i]=='S'&&ans[i+1]=='W'&&s[i+1]=='o')ans.push_back('W');
       if(ans[i]=='S'&&ans[i+1]=='W'&&s[i+1]=='x')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='S'&&s[i+1]=='o')ans.push_back('W');
       if(ans[i]=='W'&&ans[i+1]=='S'&&s[i+1]=='x')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='W'&&s[i+1]=='o')ans.push_back('S');
       if(ans[i]=='W'&&ans[i+1]=='W'&&s[i+1]=='x')ans.push_back('W');
   }
   if(ans[n-1]=='S'){
   if(((s[0]=='o'&&ans[1]!=ans[n-1])||(s[0]=='x'&&ans[1]==ans[n-1]))&&((s[n-1]=='o'&&ans[0]==ans[n-2])||(s[n-1]=='x'&&ans[n-2]!=ans[0]))){
       rep(i,n)cout<<ans[i];
       return 0;
   }
   }
     if(ans[n-1]=='W'){
   if(((s[0]=='o'&&ans[1]!=ans[n-1])||(s[0]=='x'&&ans[1]==ans[n-1]))&&((s[n-1]=='o'&&ans[0]!=ans[n-2])||(s[n-1]=='x'&&ans[n-2]==ans[0]))){
       rep(i,n)cout<<ans[i];
       return 0;
   }
   }
   cout<<-1;

  }
  
     


Measured memory_bytes: 768