
import java.io.PrintWriter;

import java.util.*;
import java.util.Arrays ; 
 
import java.io.DataInputStream; 
import java.io.FileInputStream; 
import java.io.IOException; 


public class Test{
static class Reader 
    { 
        final private int BUFFER_SIZE = 1 << 16; 
        private DataInputStream din; 
        private byte[] buffer; 
        private int bufferPointer, bytesRead; 
  
        public Reader() 
        { 
            din = new DataInputStream(System.in); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public Reader(String file_name) throws IOException 
        { 
            din = new DataInputStream(new FileInputStream(file_name)); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public String readLine() throws IOException 
        { 
            byte[] buf = new byte[64]; // line length 
            int cnt = 0, c; 
            while ((c = read()) != -1) 
            { 
                if (c == '\n') 
                    break; 
                buf[cnt++] = (byte) c; 
            } 
            return new String(buf, 0, cnt); 
        } 
  
        public int nextInt() throws IOException 
        { 
            int ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do
            { 
                ret = ret * 10 + c - '0'; 
            }  while ((c = read()) >= '0' && c <= '9'); 
  
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        public long nextLong() throws IOException 
        { 
            long ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        public double nextDouble() throws IOException 
        { 
            double ret = 0, div = 1; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
  
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
  
            if (c == '.') 
            { 
                while ((c = read()) >= '0' && c <= '9') 
                { 
                    ret += (c - '0') / (div *= 10); 
                } 
            } 
  
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        private void fillBuffer() throws IOException 
        { 
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
            if (bytesRead == -1) 
                buffer[0] = -1; 
        } 
  
        private byte read() throws IOException 
        { 
            if (bufferPointer == bytesRead) 
                fillBuffer(); 
            return buffer[bufferPointer++]; 
        } 
  
        public void close() throws IOException 
        { 
            if (din == null) 
                return; 
            din.close(); 
        } 
    } 
   

static int find(String s){
    for (int i = 0; i < s.length(); i++) {
        if(s.charAt(i)=='^'){
        return i ;
        }
    }
    return -1 ; 
}
static String ch(long[]x,long b){
    for (int i = 0; i < x.length; i++) {
        if(x[i]==b)return "YES" ;
    }
    return "NO" ; 
}

    public static void main(String[] args) throws IOException  {

    
        PrintWriter pw = new PrintWriter(System.out);   
    //   Reader  in =new Reader ();
       Scanner  in =new Scanner (System.in);
       int n =in.nextInt();
    String s= in.next() ; 
    String  r= s ; 
    char x[] =s.toCharArray() ; 
    Arrays.sort(x);
  s= new String(x) ;
   //  System.out.println(s);
    if(s.equals(r)){
        System.out.println("NO");
        return ; 
    }
    long pos =0 ; 
    long past =0 ;
    long save=0 ;
    
        for (int i = 0; i < r.length(); i++) {
            if(r.charAt(i)!=s.charAt(0)){
                past = pos ;
               pos=0 ; 
            }
            if(r.charAt(i)==s.charAt(0)){
               pos++ ; 
            }
            if(pos>=past){
                save = i ;
            }
            
        }
        int a ,b ;
      b= (int)save +1 ; 
      a=0 ;
        for (int i = 0; i < r.length(); i++) {
            if(r.charAt(i)!=r.charAt((int)save)){
                a=i ;
                break ;
            }
        }
        System.out.println("YES");
        System.out.println((a)+" "+b);
        
        pw.close();
}}