#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;

#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define all(x) begin (x), end(x)
#define sz(x) (int) (x).size()
#define rep(i,a,b) for (int i = (a); i < (b); i++)

mt19937 rng(random_device{}());

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int n;
    string s;
    cin >> n >> s;
    vi ans;
    rep(i,0,n){
        if(i == 0){
            if(s[i] == 'o') ans.pb(i+1);
        } else{
            if(s[i] == 'o' && s[i-1] == 'x') ans.pb(i+1);
        }
    }
    cout << ans.size() << endl;
    for(auto a : ans) cout << a << " ";
}