source_code: //package com.example.programming;
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Scanner;
  
  
  public class CodeforcesProblems {
  
  
      static class Pair {
          public Pair(int key, int val) {
              this.key = key;
              this.val = val;
          }
          int key;
          int val;
      }
  
  
      public static void main(String[] args) throws IOException {
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  
          //String[] strings = br.readLine().split(" ");
          int n = Integer.parseInt(br.readLine());
  
          String[] strings = br.readLine().split(" ");
          int[] arr = new int[n];
          for(int i = 0; i<n; i++) {
              arr[i] = Integer.parseInt(strings[i]);
          }
  
  
          HashMap<Integer, ArrayList<Pair>> segments = new HashMap<>();
          for(int r = 0; r<arr.length; r++) {
              int sum = 0;
              for(int l = r; l>=0; l--) {
                  sum += arr[l];
                  ArrayList<Pair> pairs = segments.get(sum);
                  if(pairs == null) {
                      pairs = new ArrayList<>();
                      segments.put(sum, pairs);
                  }
                  pairs.add(new Pair(l, r));
              }
          }
  
          int res = 0;
          ArrayList<Pair> result = new ArrayList<>();
          for(ArrayList<Pair> pairs: segments.values()) {
              ArrayList<Pair> temp = new ArrayList<>();
              int count = 0;
              int r = -1;
              for(Pair p : pairs) {
                  if(p.key>r) {
                      count++;
                      temp.add(p);
                      r = p.val;
                  }
              }
              if(count>res) {
                  res = count;
                  result = temp;
              }
          }
          System.out.println(res);
          StringBuilder sb = new StringBuilder();
          for(Pair p : result){
              sb.append(p.key+1).append(' ').append(p.val+1).append('\n');
          }
          System.out.print(sb);
      }
  }
  