// UUID: f6f69da9-624f-4d70-8d2f-83c9124fc000
#include<bits/stdc++.h>
using namespace std;
int main()
{
    int N;
    cin>>N;
    vector<int> hisztogram(N+1, 0);
    vector<int> V(N+1);
    for(int i=1; i<=N; i++)
    {
        int a;
        cin>>a;
        V[i]=a;
        hisztogram[a-1]=i;
    }
    /*for(int i=0; i<=N; i++) cout<<hisztogram[i]<<" ";
    cout<<endl;*/
    hisztogram[N]=INT_MAX;
    for(int i=N-2; i>=1; i--)
    {
        hisztogram[i]=min(hisztogram[i], hisztogram[i+1]);
    }
    int maxi=-1;
    int maxis;
    for(int i=1; i<=N; i++)
    {
        if(i-hisztogram[V[i]]>maxi)
        {
             maxi=i-hisztogram[V[i]];
             maxis=i;
        }
    }
    /*for(int i=0; i<=N; i++) cout<<hisztogram[i]<<" ";
    cout<<endl;*/
    if(maxi==-1) cout<<-1;
    else cout<<maxis-maxi<<" "<<maxis;
}