#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef string str;
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    ll n;
    str s, p = "";
    cin >> n >> s;
    ll countt = 0;
    bool check = true;
    for (ll i = 0; i < n; i++)
    {
        if (check && s[i] == 'o')
        {
            p += to_string(i + 1) + ' ';
            check = false;
            countt++;
        }
        else if (!check && s[i] == 'x') check = true;
    }
    cout << countt << "\n";
    if (countt > 0) cout << p;
    return 0;
}