#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n, t;
    cin >> n >> t;
    vector <int> s(n);
    for (int i = 0; i < n; i++)
    {
        cin >> s[i];
    }
    vector <int long long> answer;
    vector<int long long>d (n, 0);
    answer.push_back(n);
    int long long l = 0;
    int long long r = 0;
    for (int long long i = 1; i < (s.size() / 2) + 1; i++)
    {
        if (i < r)
            d[i] = min(d[l + r - i + 1], r - i + 1);
        int long long L = i - d[i], R = i + d[i] - 1;
        while(L - 1 >= 0 && R + 1< n && s[L - 1] == s[R + 1]) d[i]++, L--, R++;
        if (d[i] - i == 0)
        {
            answer.push_back(n - i);
        }
        if (R > r)
            l = L, r = R;
    }
    sort(answer.begin(), answer.end());
    for (int i = 0; i< answer.size(); i++)
    {
        if (i < answer.size() - 1)
                cout << answer[i] << " ";
        else
                cout << answer[i];
    }
    return 0;
}