#include <bits/stdc++.h>
#include <vector>

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);

	ll n;
	cin >> n;
	bool sleeping = true;
	vector<ll> vals;

	for(ll i = 1; i <= n; i++){
		char val;
		cin >> val;
		
		if(sleeping && val == 'o'){
			vals.pb(i);
			sleeping = false;
		}else if(val == 'x'){
			sleeping = true;
		}
	}

	cout << vals.size() << endl;
	for(ll i = 0; i < vals.size(); i++){
		cout << vals[i] << " ";
	}
	cout << endl;

	return 0;
}