/*
Solution Author: Grigory Reznikov
Date: 29.04.2018
*/

#include <bits/stdc++.h>

using namespace std;

constexpr int MX = 500 * 1000 + 7;

int a[MX];
int cnt[MX];
int cntcnt[MX];
int diff = 0;

void ad(int x) {
    if (cnt[x] == 0) {
        diff++;
        cnt[x] = 1;
        cntcnt[1]++;
    } else {
        cntcnt[cnt[x]]--;
        cnt[x]++;
        cntcnt[cnt[x]]++;
    }
}

void rm(int x) {
    if (cnt[x] == 1) {
        diff--;
        cnt[x] = 0;
        cntcnt[1]--;
    } else {
        cntcnt[cnt[x]]--;
        cnt[x]--;
        cntcnt[cnt[x]]++;
    }
}

void cl() {
    memset(cnt, 0, sizeof(cnt));
    memset(cntcnt, 0, sizeof(cntcnt));
    diff = 0;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    int n;
    cin >> n;

    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        ad(a[i]);
    }

    int tdiff = diff;
    cl();
    int lg = 1, rg = n + 1;
    while (rg - lg > 1) {
        int m = (lg + rg) >> 1;
        cl();
        for (int i = 1; i <= m; i++) {
            ad(a[i]);
        }
        bool ok = false;
        if (diff == m || (m != n && diff != tdiff && diff == m - 1 && cntcnt[2] != 0)) {
            ok = true;
        }
        for (int i = m + 1; i <= n; i++) {
            ad(a[i]);
            rm(a[i - m]);
            if (diff == m || (m != n && diff != tdiff && diff == m - 1 && cntcnt[2] != 0)) {
                ok = true;
            }
        }
        if (ok) {
            lg = m;
        } else {
            rg = m;
        }
    }

    cout << lg << "\n";

}