1569A

#include<bits/stdc++.h>
#define lli long long int
#define vi vector<int>
#define vlli vector<lli>
#define pii pair<int,int>
#define vpi vector<pii>
#define mp unordered_map<char,int>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define ff first
#define ss second
 
#define MOD1 1000000007
#define MOD2 1000000009
using namespace std;
signed main(){
   lli t;cin>>t;
   while(t--){
     lli n;cin>>n;
     string s;cin>>s;
     if (n==1) cout<<"-1 -1\n";
     else{
      bool ok=true;
      char ch = s[0];
      rep(i,1,n){
         if (i==0) continue;
         else if (s[i]!=ch){
            cout<<i<<" "<<i+1<<"\n";
            ok=false;
            break;
         }
      }
      if (ok) cout<<"-1 -1\n";
     }
   }
    return 0;
}