#include <bits/stdc++.h>
//#include <atcoder/all>
#define yes cout << "Yes" << '\n'
#define no cout << "No" << '\n'
#define YES cout << "YES" << '\n'
#define NO cout << "NO" << '\n'
#define OK cout << "OK" << '\n'
#define NG cout << "NG" << '\n'
#define Yes "Yes"
#define No "No"
#define Takahashi cout << "Takahashi" << '\n'
#define Aoki cout << "Aoki" << '\n'
#define minus cout << -1 << '\n'
#define br cout << '\n'
#define nl '\n'
#define sadFace ":("
#define circle 'o'
#define cross 'x'
#define elif else if
#define len(s) (int)s.length()
#define sz size
#define it insert
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define ll long long
#define ull unsigned long long
#define ft first
#define sd second
#define ctz(x) __builtin_ctz(x);
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep1(i, n) for (int i = 1; i <= (n); i++)
#define MIN(v) *min_element(all(v))
#define MAX(v) *max_element(all(v))
#define all(v) v.begin(), v.end()
#define lla(v) rbegin(v), rend(v)
#define vecTotal(v) accumulate(v.begin(), v.end(), 0)
#define ruisekiwa(v, e) partial_sum(v.begin(), v.end(), back_inserter(e))
using namespace std;
//using namespace atcoder;

template <typename T>
T div_ceil(T a, T b) { // 切り上げ除算
	return (a >= 0 ? (a + b - 1) : a) / b;
}

template <typename T>
T div_floor(T a, T b) { // 切り捨て除算
	return a / b - (a % b < 0);
}

template <typename T>
void grid_input(vector<vector<T>> &v, T h, T w) {
    rep(i,h) {
        rep(j,w) {
            cin >> v[i][j];
        }
    }
}

template <typename T>
void vin(vector<T> &v, T n) {
    rep(i,n) cin >> v[i];
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int a,ans = 0;
    cin >> a;
    bool isSleep = false;
    vector<int> v;
    rep1(i,a) {
        char c;
        cin >> c;
        if(!isSleep) {
            if(c == circle) {
                isSleep = true;
                ans++;
                v.pb(i);
                }
        } else {
            if(c == cross) {
                isSleep = false;
            }
        }
    }
    cout << ans << nl;
    for(int i : v) {
        cout << i << ' ';
    }
    br;
}