#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 {}());

void solve(){
    int n;
    vi count;
    string s;
    cin >> n;
    cin >> s;
    for(int i = 0; i < n; i++){
        if((s[i] == 'o' && s[i - 1] == 'x') || s[0] == 'o'){
            count.push_back(i+1);
        }
    }
    cout << count.size() << endl;
    for(auto x : count)
        cout << x << " ";
    
}

int main()
{
    cin.tie(0)->sync_with_stdio(0);
    solve();
    return 0;
}