source_code: import java.io.*;
  import java.util.*;
  import java.math.*;
  import java.awt.Point;
  
  public final class Solution {
      BufferedReader br;
      StringTokenizer st;
      
      {
          st = null;
          br = new BufferedReader(new InputStreamReader(System.in));
      }
      
      public static void main(String[] args) throws Exception {
          new Solution().run();
      }
      
      void run() throws Exception {
          int n = ni();
          int[] a = new int[n];
          for(int i=0; i<n; i++) a[i] = ni();
          for(int i=1; i<n; i++) a[i] += a[i-1];
          
          HashMap<Integer, List<Point>> map = new HashMap<>();
          for(int i=0; i<n; i++) {
              for(int j=i; j<n; j++) {
                  int sum = getSum(a, i, j);
                  if(!map.containsKey(sum)) map.put(sum, new ArrayList<>());
                  map.get(sum).add(new Point(i+1, j+1));
              }
          }
          
          for(int key : map.keySet()) {
              Collections.sort(map.get(key), new Comparator<Point>() {
                  @Override
                  public int compare(Point p1, Point p2) {
                      if(p1.x == p2.x) return p1.y - p2.y;
                      return p1.x - p2.x;
                  }
              });
          }
          
          Stack<Point> stack = new Stack<>();
          for(int key : map.keySet()) {
              Stack<Point> st = getPairs(map.get(key));
              if(st.size() > stack.size()) stack = st;
          }
          
          pl(stack.size());
          while(!stack.isEmpty()) {
              Point p = stack.pop();
              pl(p.x + " " + p.y);
          }
      }
      
      Stack<Point> getPairs(List<Point> list) {
          Stack<Point> stack = new Stack<>();
          stack.push(list.get(0));
          for(int i=1; i<list.size(); i++) {
              Point p = list.get(i);
              if(p.x >= stack.peek().x && p.x <= stack.peek().y) {
                  Point p2 = stack.pop();
                  if(p2.y < p.y) {
                      stack.push(p2);
                  } else {
                      stack.push(p );
                  }
              } else {
                  stack.push(p);
              }
          }
          return stack;
      }
      
      int getSum(int[] a, int l, int r) {
          return (l == 0) ? a[r] : a[r] - a[l-1];
      }
      
      class Node {
          HashSet<Integer> adj;
          public Node() {
              adj = new HashSet<>();
          }
      }
      
      // I/O
      String nt() throws Exception {
          if(st == null || !st.hasMoreTokens()) {
              st = new StringTokenizer(br.readLine(), " ");
          }
          return st.nextToken();
      }
      
      int ni() throws Exception {
          return Integer.parseInt(nt());
      }
      
      long nl() throws Exception {
          return Long.parseLong(nt());
      }
      
      void p(Object o) {
          System.out.print(o);
      }
      
      void pl(Object o) {
          System.out.println(o);
      }
  }