#include <bits/stdc++.h>
using namespace std;
#define int              long long int
#define double           long double
#define print(a)         for(auto x : a) cout << x << " "; cout << endl


const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;

inline int power(int a, int b, int mod=M) {
    int x = 1;
    a %= mod;
    while (b) {
        if (b & 1) x = (x * a) % mod; 
        a = (a * a) % mod;
        b >>= 1;
    }
    return x;
}


//_ ***************************** START Below *******************************




vector<int> a;

vector<pair<int,int>> consistency(int n){

    unordered_map<int,int> mp;
    int k = 0;

    vector<pair<int,int>> ans;

    for(int i=0; i<n; i++){
        if(mp.count(a[i])){
            int j = mp[a[i]];
            if(j>=k){
                mp.erase(a[i]);
                ans.push_back({k+1, i+1});
                k = i+1;
            }
        }
        mp[a[i]] = i;
    }


    return ans;

}















vector<pair<int,int>> practice(int n){


}





void solve() {
    
    int n;
    cin>> n;
    
    a.resize(n);
    for(int i=0; i<n; i++) cin >> a[i];
    
    auto ans = consistency(n);
    if(ans.size() == 0){
        cout << -1 << endl;
        return;
    }
    cout << ans.size() << endl;
    for(auto& t : ans) cout << t.first << " " << t.second << endl;


}





int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}