#include <bits/stdc++.h>
using namespace std;
ifstream in("secv.in");
ofstream out("secv.out");
int v[2000005];
map <int, int> c;
int fr[50005];
int f[50005];
int p[50005];
int dp[50005];
int main()
{
    int n;
    in >> n;
    for(int i = 0; i < n; i ++)
    {
        in >> v[i];
        if(fr[v[i]] == 0)
        {
            c[v[i]] ++;
            fr[v[i]] = 1;
        }
    }
    int pos = -1;
    for(auto it : c)
    {
        ++pos;
        fr[it.first] = pos;
    }
    for(int i = 0; i < n; i ++)
    {
        v[i] = fr[v[i]];
        if(v[i] == 0)
            p[i] = i;
        else
            p[i] = f[v[i] - 1];
        f[v[i]] = i;
    }
    int mn = (1 << 30);
    for(int i = 0; i < n; i ++)
    {
        if(p[i] != 0)
            dp[i] = dp[p[i]] + i - p[i];
        else
            dp[i] = (1 << 30);
        if(v[i] + 1 == c.size())
            mn = min(mn, dp[i]);
    }
    if(mn == (1 << 30))
    {
        out << "-1";
        return 0;
    }
    out << mn + 1;
    return 0;
}