simulare osepi MMXI

#include <bits/stdc++.h>
using namespace std;
const int NMAX = 5e5 + 3;
int n, a[NMAX], pi[NMAX];

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

signed main() {
    read();
    for (int i = 2; i <= n; i++) {
        int curr = pi[i - 1];
        while (curr > 0 && a[curr + 1] != a[i]) {
            curr = pi[curr];
        }
        if (a[curr + 1] == a[i]) {
            curr++;
        }
        pi[i] = curr;
    }
    cout << n - pi[n] << endl;
    return 0;
}