#include<bits/stdc++.h>
using namespace std;
//#include<atcoder/all>
//using namespace atcoder;
using ll = long long;
using ull = unsigned long long;
#define rep(i,n) for(int i=0;i<(n);++i)

int main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n;
	cin >> n;
	string s;
	cin >> s;

	vector<int> ans;
	for(int i=0;i<n;++i){
		if(s[i]=='o')ans.emplace_back(i+1);
		while(i+1<n && s[i]==s[i+1]){
			i++;
		}
	}

	int m = ans.size();
	cout << m << endl;
	for(int i=0;i<m;++i) cout << ans[i] << " ";
}