source_code: import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.util.Iterator;
  import java.util.Set;
  import java.util.HashMap;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.StringTokenizer;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.io.BufferedReader;
  import java.io.InputStream;
  
  /**
   * Built using CHelper plug-in
   * Actual solution is at the top
   *
   * @author Washoum
   */
  public class Main {
      public static void main(String[] args) {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          inputClass in = new inputClass(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          F2SameSumBlocksHard solver = new F2SameSumBlocksHard();
          solver.solve(1, in, out);
          out.close();
      }
  
      static class F2SameSumBlocksHard {
          public void solve(int testNumber, inputClass sc, PrintWriter out) {
              int n = sc.nextInt();
              int[] tab = new int[n];
              int[] s = new int[n];
              for (int i = 0; i < n; i++) {
                  tab[i] = sc.nextInt();
                  if (i > 0)
                      s[i] = s[i - 1] + tab[i];
                  else
                      s[0] = tab[0];
              }
              HashMap<Integer, F2SameSumBlocksHard.Pair> sums = new HashMap<>();
              F2SameSumBlocksHard.Pair p;
              for (int i = 0; i < n; i++) {
                  for (int j = 0; j <= i; j++) {
                      if (j > 0) {
                          if (sums.get(s[i] - s[j - 1]) != null) {
                              if (sums.get(s[i] - s[j - 1]).last < j) {
                                  sums.get(s[i] - s[j - 1]).sum++;
                                  sums.get(s[i] - s[j - 1]).last = i;
                              }
                          } else {
                              p = new F2SameSumBlocksHard.Pair();
                              p.sum = 1;
                              p.last = i;
                              sums.put(s[i] - s[j - 1], p);
                          }
                      } else {
                          if (sums.get(s[i]) != null) {
                              if (sums.get(s[i]).last < j) {
                                  sums.get(s[i]).sum++;
                                  sums.get(s[i]).last = i;
                              }
                          } else {
                              p = new F2SameSumBlocksHard.Pair();
                              p.sum = 1;
                              p.last = i;
                              sums.put(s[i], p);
                          }
                      }
                  }
              }
  
              Iterator<Map.Entry<Integer, F2SameSumBlocksHard.Pair>> it = sums.entrySet().iterator();
              Map.Entry<Integer, F2SameSumBlocksHard.Pair> t;
              int maxsum = 0;
              int cnt = 0;
              while (it.hasNext()) {
                  t = it.next();
                  if (t.getValue().sum > cnt) {
                      maxsum = t.getKey();
                      cnt = t.getValue().sum;
                  }
              }
  
              out.println(cnt);
              int start = 0;
              for (int i = 0; i < n; i++) {
                  for (int j = start; j <= i; j++) {
                      if (j > 0) {
                          if (s[i] - s[j - 1] == maxsum) {
                              out.println((j + 1) + " " + (i + 1));
                              start = i + 1;
                              break;
                          }
                      } else {
                          if (s[i] == maxsum) {
                              out.println((j + 1) + " " + (i + 1));
                              start = i + 1;
                              break;
                          }
                      }
                  }
              }
  
  
          }
  
          static class Pair {
              int sum;
              int last;
  
          }
  
      }
  
      static class inputClass {
          BufferedReader br;
          StringTokenizer st;
  
          public inputClass(InputStream in) {
  
              br = new BufferedReader(new InputStreamReader(in));
          }
  
          public String next() {
              while (st == null || !st.hasMoreElements()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
  
          public int nextInt() {
              return Integer.parseInt(next());
          }
  
      }
  }
  
  