source_code: import java.io.BufferedReader;
  import java.io.FileNotFoundException;
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  public class F1141 {
  	
  	private static class Interval {
  		public int l;
  		public int r;
  		
  		public Interval(int l,int r) {
  			this.l = l;
  			this.r = r;
  		}
  	}
  
  	public static void main(String[] args) throws IOException {
  //		BufferedReader br = new BufferedReader(new FileReader("F:/books/input.txt"));
  		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  		String s = br.readLine();
  		int n = Integer.parseInt(s);
  		long[] a = new long[n];
  		String[] as = br.readLine().split(" ");
  		for(int i=0;i<n;i++) {
  			a[i] = Long.parseLong(as[i]);
  		}
  		StringBuffer sb = solve(a,n);
  		System.out.println(sb.toString());
  	}
  
  	private static StringBuffer solve(long[] a, int n) {
  		StringBuffer ret = new StringBuffer("");
  		Map<Long,List<Interval>> mp = new HashMap<Long,List<Interval>>();
  		long max = 0,maxId = -1;
  		for(int i=n-1;i>=0;i--) {
  			long s=0;
  			long prev = 1;
  			for(int j=i;j<n;j++) {
  				s+=a[j];
  //				System.out.println(i+","+j);
  				Interval inter = new Interval(i,j);
  //				if(prev==1 || prev==-1) {
  					List<Interval> ints = mp.get(s);
  					if(ints==null) ints = new ArrayList<Interval>();
  					if(ints.size()==0 || ints.get(0).l>j) {
  						ints.add(0,inter);
  					}
  					if(ints.size()>max) {
  						max = ints.size();
  						maxId = s;
  					}
  					mp.put(s, ints);
  //				}
  				if(j<n-1) prev =  a[j+1]-a[j];
  			}
  		}
  		List<Interval> l = mp.get(maxId);
  		ret.append(l.size()+ "\n");
  		for(Interval inter : l) {
  			ret.append((inter.l+1) + " " + (inter.r+1) + "\n");
  		}
  		return ret;
  	}
  
  }
  