source_code: import java.io.*;
  import java.util.*;
  
  public class Soln {
  	
  	public static int[] io(int n) {
      	int[] d = new int[n];
      	for (int i=0;i<n;i++) d[i] = f.nextInt();
      	return d;
  	}
  	public static int binlog( int bits ){
          int log = 0;
          if( ( bits & 0xffff0000 ) != 0 ) { bits >>>= 16; log = 16; }
          if( bits >= 256 ) { bits >>>= 8; log += 8; }
          if( bits >= 16  ) { bits >>>= 4; log += 4; }
          if( bits >= 4   ) { bits >>>= 2; log += 2; }
          return log + ( bits >>> 1 );
      }
  	static class FastReader { 
          BufferedReader br; 
          StringTokenizer st; 
    
          public FastReader() 
          { 
              br = new BufferedReader(new
                       InputStreamReader(System.in)); 
          } 
    
          String next() 
          { 
              while (st == null || !st.hasMoreElements()) 
              { 
                  try
                  { 
                      st = new StringTokenizer(br.readLine()); 
                  } 
                  catch (IOException  e) 
                  { 
                      e.printStackTrace(); 
                  } 
              } 
              return st.nextToken(); 
          } 
    
          int nextInt() 
          { 
              return Integer.parseInt(next()); 
          } 
    
          long nextLong() 
          { 
              return Long.parseLong(next()); 
          } 
    
          double nextDouble() 
          { 
              return Double.parseDouble(next()); 
          } 
    
          String nextLine() 
          { 
              String str = ""; 
              try
              { 
                  str = br.readLine(); 
              } 
              catch (IOException e) 
              { 
                  e.printStackTrace(); 
              } 
              return str; 
          } 
  	}
  	public static final long mod = (long)Math.pow(10, 9) + 7;
  	static FastReader f=new FastReader();
  	
  	public static void main (String[] args) throws IOException{
  		int n = f.nextInt();
  		int[] a = io(n);
  		HashMap<Integer,ArrayList<ivl>> hm = new HashMap<>();
  		for (int i=0;i<n;i++) {
  			int sum = 0;
  			for (int j=i;j<n;j++) {
  				sum+=a[j];
  				if (hm.get(sum)==null) hm.put(sum,new ArrayList<ivl>());
  				hm.get(sum).add(new ivl(i,j));
  			}
  		}
  		HashSet<ivl> hs = new HashSet<ivl>();
  		
  		for (ArrayList<ivl> arr : hm.values()) {
  			Collections.sort(arr,new comp());
  			HashSet<ivl> temp = new HashSet<ivl>();
  			temp.add(arr.get(0));
  			int lastr = arr.get(0).r;
  			int num = 1;
  			for (ivl curr:arr) {
  				if (curr.l>lastr) {
  					lastr = curr.r;
  					num++;
  					temp.add(curr);
  				}
  			}
  			if (temp.size()>hs.size()) hs = temp;
  		}
  		
  		System.out.println(hs.size());
  		for (ivl curr:hs) {
  			System.out.println((curr.l+1)+" "+(curr.r+1));
  		}
      }
  	
  	static class ivl{
  		int l,r;
  		ivl(int l,int r){
  			this.l=l;this.r=r;
  		}
  	}
  	
  	static class comp implements Comparator<ivl>{
  		public int compare(ivl a,ivl b) {
  			if (a.r - b.r == 0) return a.l-b.l;
  			return a.r-b.r;
  		}
  	}
  }