#include <cstdio>
#include <algorithm>

using namespace std;

int v[50001],v1[50001],v2[50001];

int main()
{
    int n,i,j,val,st,last,lmin=2000000000,k,l;
    freopen("secv.in","r",stdin);
    freopen("secv.out","w",stdout);
    scanf("%d", &n);
    for (i=1;i<=n;i++)
        scanf("%d", &v[i]),v1[i]=v[i];
    sort(v1+1,v1+n+1);
    k=1;
    v2[k]=v1[k];
    last=v1[k];
    for (i=2;i<=n;i++)
        if (v1[i]!=last)
            v2[++k]=v1[i],last=v1[i];
    for (i=1;i<=n;i++)
        if (v[i]==1) {
            val=2;
            for (j=i+1;j<=n;j++)
                if (v[j]==val) {
                    val++;
                    if (val==k+1) {
                        l=j-i+1;
                        if (l<lmin)
                            lmin=l;
                        break;
                    }
                }
        }
    printf("%d", lmin);
    return 0;
}