#include<fstream>
#include<algorithm>
using namespace std;
int a[5001],sortat[5001],individual[5001],n;
int main(){
	ifstream f("secv.in");
	ofstream g("secv.out");
	f>>n;

	int i;
	for(i=1;i<=n;i++){
		f>>sortat[i];
		a[i]=sortat[i];
	}
	
	sort(sortat,sortat+n);
	
	int ct=0;
	for(i=1;i<=n;i++){
		if(i==1){
			if(sortat[i]==0){
				ct++;
				individual[ct]=0;
			}
		}
		if(sortat[i]!=sortat[i-1] ){
			
			ct++;
			individual[ct]=sortat[i];
			
		}
	}
	int min=5000;
	int ct1=1,in=0,cv=1;
	short ok=0;
	
	while(cv<=n-ct){
		in=0;
		ct1=1;
		for(i=cv;i<=n;i++){
		
			in++;
			cout<<a[i]<<" "<<individual[ct1]<<" "<<ct1<<" "<<in<<"\n";
			if(a[i]==individual[ct1]){
				ct1++;
				if(ct1>ct){
					if(min>in){
						ok=1;
						min=in;
					}
					ct1=1;
					in=0;
				}
			}
		}
		cv++;
	}
	if(ok==1){
	g<<min;
	}
	else{
		g<<"-1";
	}
	return 0;
}