#include <bits/stdc++.h>
using namespace std;
ifstream f("secv.in");
ofstream g("secv.out");
#define cin f
#define cout g
//#define int long long
const int Max = 5e3 + 1;
void nos()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}
int n;
int a[Max];
void read()
{
    f>>n;
    int i;
    for(i=1;i<=n;i++)
        f>>a[i];
}
int who[Max];
void update(int poz, int val)
{
    who[poz] = max(who[poz],val);
}
std::vector< int > all;
int norma(int x)
{
    auto it = lower_bound(all.begin(),all.end(),x);
    return distance(all.begin(),it) + 1;
}
void solve()
{   
    
    int i;
    for(i=1;i<=n;i++)
        all.push_back(a[i]);
    sort(all.begin(), all.end());
    all.erase(unique(all.begin(), all.end()),all.end());
    //dp[i] --> maximum starting point
    for(i=1;i<=all.size();i++)
        who[i] = -1;
    int ans = INT_MAX;
    for(i=1;i<=n;i++)
    {
        int poz = norma(a[i]);
        if(poz == 1)
            update(poz,i);
        else
        {
            int prev_best = who[poz - 1];
            update(poz,prev_best);
        }
        if(poz == all.size() and who[all.size()] != -1)
        {
            //daca e ultimul vad ce valoare avem aici
            int this_best = i - who[all.size()] + 1;
            ans = min(ans,this_best);
        }
    }
    if(ans != INT_MAX)
    cout<<ans;
    else
    cout<<-1;
}
void restart()
{
 
}
int32_t main()
{
    nos();
 
        read();
        solve();
        restart();
    
    return 0;
}