#include <fstream>
#include <algorithm>
using namespace std;
fstream in("secv.in");
ofstream out("secv.out");
int v[5100],a[5100],b[5100],minim=5100,n,i,j,aux,k=1;
int main()
{
    in>>n;
    for(i=1;i<=n;i++)
    {
        in>>v[i];
        a[i]=v[i];
    }
    sort(a+1,a+n+1);
    b[1]=a[1];
    for(i=2;i<=n;i++)
    {
        if(a[i]!=a[i-1])
        {
        k++;
        b[k]=a[i];
        }

    }

    for(i=1;i<=n;++i)
    {
        if(v[i]==b[1])
        {
            aux=0;
            for(j=i;j<=n;++j)
            {
                if(v[j]==b[aux+1])
                    ++aux;
                if(aux==k && j-i+1<=minim)
                    minim=j-i+1;
            }
        }
    }
    if(minim==5100)
        minim=-1;
    out<<minim<<'\n';
    return 0;
}