source_code: import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.io.BufferedInputStream;
  import java.util.HashMap;
  import java.util.ArrayList;
  import java.io.FilterInputStream;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Comparator;
  import java.util.Collections;
  import java.io.InputStream;
  
  /**
   * Built using CHelper plug-in
   * Actual solution is at the top
   *
   * @author Jenish
   */
  public class Main {
      public static void main(String[] args) {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          ScanReader in = new ScanReader(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, ScanReader in, PrintWriter out) {
              int n = in.scanInt();
              long arr[] = new long[n];
              for (int i = 0; i < n; i++) {
                  arr[i] = in.scanLong();
              }
  
  
              HashMap<Long, ArrayList<pair>> hm = new HashMap<>();
              for (int i = 0; i < n; i++) {
                  long sum = 0;
                  for (int j = i; j < n; j++) {
                      sum += arr[j];
                      if (hm.containsKey(sum)) {
                          hm.get(sum).add(new pair(i + 1, j + 1));
                      } else {
                          hm.put(sum, new ArrayList<>());
                          hm.get(sum).add(new pair(i + 1, j + 1));
                      }
                  }
              }
  
  
              long maxi_sum = -1;
              long sum = 0;
              for (Map.Entry<Long, ArrayList<pair>> k : hm.entrySet()) {
                  Collections.sort(k.getValue(), new Comparator<pair>() {
  
                      public int compare(pair o1, pair o2) {
                          return o1.r - o2.r;
                      }
                  });
  
                  int count = k.getValue().size() > 0 ? 1 : 0;
                  int index = 0;
                  for (int i = 1; i < k.getValue().size(); i++) {
                      if (k.getValue().get(i).l > k.getValue().get(index).r) {
                          count++;
                          index = i;
                      }
                  }
  
  
                  if (count > maxi_sum) {
                      maxi_sum = count;
                      sum = k.getKey();
                  }
              }
  
              out.println(maxi_sum);
              ArrayList<pair> tt = hm.get(sum);
              Collections.sort(tt, new Comparator<pair>() {
  
                  public int compare(pair o1, pair o2) {
                      return o1.r - o2.r;
                  }
              });
  
  
              out.println(tt.size() > 0 ? (tt.get(0).l + " " + tt.get(0).r) : (" "));
              int index = 0;
              for (int i = 1; i < tt.size(); i++) {
                  if (tt.get(i).l > tt.get(index).r) {
                      out.println(tt.get(i).l + " " + tt.get(i).r);
                      index = i;
                  }
              }
  
  
          }
  
          class pair {
              int l;
              int r;
  
              public pair(int l, int r) {
                  this.l = l;
                  this.r = r;
              }
  
          }
  
      }
  
      static class ScanReader {
          private byte[] buf = new byte[4 * 1024];
          private int INDEX;
          private BufferedInputStream in;
          private int TOTAL;
  
          public ScanReader(InputStream inputStream) {
              in = new BufferedInputStream(inputStream);
          }
  
          private int scan() {
              if (INDEX >= TOTAL) {
                  INDEX = 0;
                  try {
                      TOTAL = in.read(buf);
                  } catch (Exception e) {
                      e.printStackTrace();
                  }
                  if (TOTAL <= 0) return -1;
              }
              return buf[INDEX++];
          }
  
          public int scanInt() {
              int I = 0;
              int n = scan();
              while (isWhiteSpace(n)) n = scan();
              int neg = 1;
              if (n == '-') {
                  neg = -1;
                  n = scan();
              }
              while (!isWhiteSpace(n)) {
                  if (n >= '0' && n <= '9') {
                      I *= 10;
                      I += n - '0';
                      n = scan();
                  }
              }
              return neg * I;
          }
  
          private boolean isWhiteSpace(int n) {
              if (n == ' ' || n == '\n' || n == '\r' || n == '\t' || n == -1) return true;
              else return false;
          }
  
          public long scanLong() {
              long I = 0;
              int n = scan();
              while (isWhiteSpace(n)) n = scan();
              int neg = 1;
              if (n == '-') {
                  neg = -1;
                  n = scan();
              }
              while (!isWhiteSpace(n)) {
                  if (n >= '0' && n <= '9') {
                      I *= 10;
                      I += n - '0';
                      n = scan();
                  }
              }
              return neg * I;
          }
  
      }
  }
  
  