// Source: https://usaco.guide/general/io

#include <algorithm>
#include <bits/stdc++.h>
using namespace std;

int main() {
	int n;
	cin>>n;
	vector<int> keres(n+1); 
	for (int i=0; i<n;i++){
		int c;
		cin>>c;
		keres[c]=i+1;
	
	}
	vector<int> dp(n+1);
	dp[1]=-1;
	int ans=-1;
	pair<int, int> ans2; 
	pair<int,int> lj={1,keres[1]};
	for (int i=2; i<=n;i++){
		if (lj.second>keres[i]){
			dp[i]=lj.second;
		}
		else{
			dp[i]=-1;
			lj.second=keres[i];
			lj.first=i;
		}
			if (dp[i]!=-1){
				if (ans<dp[i]-keres[i]){
					ans=dp[i]-keres[i];
					ans2=make_pair(keres[i], dp[i]);
				}	
			}

	}
if (ans==-1){
	cout<<-1;
	return 0; 
}	
cout<<ans2.first<<" "<<ans2.second; 
}