#include <iostream>
#include <vector>
#include <set>
#include <map>

using namespace std;

int main()
{
    int n,max;
    cin>>n;
    pair<int,int> best;
    best.first=2;
    best.second=1;
    set<int> bs;
    vector<int> data(n);
    map<int,int> stor;
    for(int i=0;i<n;i++)
        {
        cin>>data[i];
        }
    max=data[0];
    bs.insert(data[0]);
    stor[data[0]]=1;
    int cnt=2;
    for(int i=1;i<n;i++)
    {
    if(max>data[i])
        {
        if(i-stor[*bs.upper_bound(data[i])]>(best.second-best.first-1))
            {
            best.second=i+1;
            best.first=stor[*bs.upper_bound(data[i])];

            }
        }
    else if(max<data[i])
        {
        bs.insert(data[i]);
        max=data[i];
        stor[data[i]]=i+1;
        cnt++;
        }

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


    return 0;
}