#include <iostream>
#include <vector>
#include <string>
#include <iomanip>
#include <queue>
#include <cmath>
#include <algorithm>
#include <tuple>
#include <iomanip>
#include <stdio.h>
#include <numeric>
#include <map>
#include <bitset>
#include <set>
#include <stack>
#include <queue>

/*
#pragma GCC optimize("Ofast,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("fast-math")
#pragma GCC optimize("section-anchors")
#pragma GCC optimize("profile-values,profile-reorder-functions,tracer")
#pragma GCC optimize("vpt")
#pragma GCC optimize("rename-registers")
#pragma GCC optimize("move-loop-invariants")
#pragma GCC optimize("unswitch-loops")
#pragma GCC optimize("function-sections")
#pragma GCC optimize("data-sections")
#pragma GCC optimize("branch-target-load-optimize")
#pragma GCC optimize("branch-target-load-optimize2")
#pragma GCC optimize("btr-bb-exclusive")
*/

#define int long long
#define ll long long
#define ull unsigned long long
#define all(a) a.begin(), a.end()
#define pii pair<int, int>
#define pb push_back
#define ld long double


using namespace std;

const int INF = 1e13;
 const int mod = 2600000069;
 const int p = 179;

ll n, m;
vector<ll> a, h, hr, pw(1000001);

inline ll subh(vector<ll>& h, ll l, ll r) {
    ll big = h[r], small = 0;
    if (l > 0) {
        small = (h[l - 1] * pw[r - l + 1]) % mod;
    }
    return (big - small + mod) % mod;
}

bool pal(ll ind) {
    //    cout << subh(hr, n - ind, n - 1) << " " << subh(h, ind, ind + ind - 1) << "\n";
    if (subh(hr, n - ind, n - 1) == subh(h, ind, ind + ind - 1)) {
        return true;
    }
    return false;
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
//    freopen("input.in", "r", stdin);
//    freopen("output.out", "w", stdout);
    cin >> n >> m;
    a.resize(n);
    for (ll i = 0; i < n; i++) {
        cin >> a[i];
    }
    h.resize(n);
    hr.resize(n);
    pw[0] = 1;
    for (ll i = 1; i < 1000001; i++) {
        pw[i] = (pw[i - 1] * p) % mod;
    }
    h[0] = a[0];
    hr[n - 1] = a[n - 1];
    for (ll i = 1; i < n; i++) {
        h[i] = (h[i - 1] * p + a[i]) % mod;
    }
    for (ll i = n - 2; i >= 0; i--) {
        hr[i] = (hr[i + 1] * p + a[i]) % mod;
    }
    reverse(all(hr));
    vector<ll> ans;
    for (int i = 1; i <= n / 2; i++) {
        if (pal(i)) {
            ans.pb(n - i);
        }
    }
    bool ok = true;
    for (int i = 0; i <= n / 2; i++) {
        if (a[i] != a[n - i - 1]) {
            ok = false;
            break;
        }
    }
    reverse(all(ans));
    for (auto x: ans) {
        cout << x << " ";
    }
    cout << n;
}