var 2

#include <iostream>
#include <map>

using namespace std;

int main()
{
    int n;
    cin >> n;
    map<int, int> mp;
    for(int i = 0; i < n; ++i)
    {
        int a;
        cin >> a;
        if(mp.count(a) == 1)
        {
            cout << mp[a] << ' ' << i + 1 << '\n';
            return 0;
        }
        mp[a] = i + 1;

    }
    cout << "NO\n";
    return 0;
}