source_code: import java.util.*;
  import java.io.*;
  import static java.lang.Math.*;
  public class Main {
      static final long MOD = 1_000_000_007, INF = 1_000_000_000_000_000_000L;
      static final int INf = 1_000_000_000;
      static FastReader reader;
      static PrintWriter writer;
      public static void main(String[] args) {
          Thread t = new Thread(null, new O(), "Integer.MAX_VALUE", 100000000);
          t.start();
      }
      static class O implements Runnable {
          public void run() {
              try {
                  magic();
              }
              catch (Exception e) {
                  e.printStackTrace();
                  System.exit(1);
              }
          }
      }
      static class FastReader {
          final private int BUFFER_SIZE = 1 << 16;
          private DataInputStream din;
          private byte[] buffer;
          private int bufferPointer, bytesRead;
  
          public FastReader() {
              din = new DataInputStream(System.in);
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
  
          public FastReader(String file_name) throws IOException {
              din = new DataInputStream(new FileInputStream(file_name));
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
  
          public String readLine() throws IOException {
              byte[] buf = new byte[1000000];
              int cnt = 0, c;
              while ((c = read()) != -1) {
                  if (c == '\n') break;
                  buf[cnt++] = (byte) c;
              }
              return new String(buf, 0, cnt);
          }
  
          public int nextInt() throws IOException {
              int ret = 0;
              byte c = read();
              while (c <= ' ') c = read();
              boolean neg = (c == '-');
              if (neg) c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
              if (neg) return -ret;
              return ret;
          }
  
          public long nextLong() throws IOException {
              long ret = 0;
              byte c = read();
              while (c <= ' ') c = read();
              boolean neg = (c == '-');
              if (neg) c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
              if (neg) return -ret;
              return ret;
          }
  
          public double nextDouble() throws IOException {
              double ret = 0, div = 1;
              byte c = read();
              while (c <= ' ') c = read();
              boolean neg = (c == '-');
              if (neg) c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
              if (c == '.') while ((c = read()) >= '0' && c <= '9') ret += (c - '0') / (div *= 10);
              if (neg) return -ret;
              return ret;
          }
  
          private void fillBuffer() throws IOException {
              bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
              if (bytesRead == -1) buffer[0] = -1;
          }
  
          private byte read() throws IOException {
              if (bufferPointer == bytesRead) fillBuffer();
              return buffer[bufferPointer++];
          }
  
          public void close() throws IOException {
              if (din == null) return;
              din.close();
          }
      }
      static void magic() throws IOException {
          reader = new FastReader();
          writer = new PrintWriter(System.out, true);
          Map<Integer, ArrayList<Pair>> map = new HashMap<>();
          int n = reader.nextInt();
          int arr[] = new int[n];
          for(int i=0;i<n;++i) {
              arr[i] = reader.nextInt();
          }
          for(int i=0;i<n;++i) {
              int sum = 0;
              for(int j=i;j<n;++j) {
                  sum+=arr[j];
                  ArrayList<Pair> list = map.get(sum);
                  if(list==null) {
                      list = new ArrayList<>();
                  }
                  list.add(new Pair(i+1,j+1));
                  map.put(sum, list);
              }
          }
          int ans = 0,at = -1;
          for(int e : map.keySet()) {
              ArrayList<Pair> list = map.get(e);
              Collections.sort(list);
  //            writer.println("Pairs having sum: "+e);
  //            for(Pair p : list) {
  //                writer.print(p);
  //                writer.print(" ");
  //            }
  //            writer.println();
              int ispe = 0;
              int len = list.size();
              for(int i=0;i<len;++i) {
                  ispe++;
                  int r = list.get(i).y;
                  while(i+1<len && list.get(i+1).x<=r) {
                      i++;
                  }
              }
              if(ans<ispe) {
                  ans = ispe;
                  at = e;
              }
          }
          writer.println(ans);
          ArrayList<Pair> list = map.get(at);
          Collections.sort(list);
          int len = list.size();
          for(int i=0;i<len;++i) {
              writer.println(list.get(i).x+" "+list.get(i).y);
              int r = list.get(i).y;
              while(i+1<len && list.get(i+1).x<=r) {
                  i++;
              }
          }
      }
      static class Pair implements Comparable<Pair> {
          int x,y;
          Pair(int x, int y) {
              this.x = x;
              this.y = y;
          }
          public int compareTo(Pair other) {
              if(this.y!=other.y) {
                  return this.y - other.y;
              }
              return this.x - other.x;
          }
          public String toString() {
              return "{" + x + "," + y + "}";
          }
      }
  }