#include <stdio.h>
#include <map>
#include <algorithm>

using namespace std;

int x[5100], uq[5100];
map <int, bool> used;

int main()
{
    int i, j, n = 0, N;

    freopen("secv.in", "r", stdin);
    freopen("secv.out", "w", stdout);

    scanf("%d", &N);
    for (i = 1; i <= N; i ++)
    {
        scanf("%d", &x[i]);
        if (used[x[i]] == 0)
        {
            uq[++ n] = x[i];
            used[x[i]] = 1;
        }
    }

    sort(uq + 1, uq + n + 1);

    int best = 1 << 30;

    for (i = 1; i <= N; i ++)
        if (x[i] == uq[1])
        {
            int matched = 1;
            for (j = i + 1; j <= N + 1; j ++)
            {
                if (matched == n)
                {
                    int ret = j - i;
                    if (ret < best)
                        best = ret;
                    break;
                }
                if (x[j] == uq[matched + 1])
                    matched ++;
            }
        }

    if (best == 1 << 30)
        best = -1;

    printf("%d", best);
    return 0;
}