source_code: import java.io.*;
  import java.util.*;
  
  public class Main {
  
      public static void main(String[] args) throws Exception {
  
          new Main().go();
      }
  
      PrintWriter out;
      Reader in;
      BufferedReader br;
  
      Main() throws IOException {
  
          try {
  
              //br = new BufferedReader( new FileReader("input.txt") );
              //in = new Reader("input.txt");
              in = new Reader("input.txt");
              out = new PrintWriter( new BufferedWriter(new FileWriter("output.txt")) );
          }
          catch (Exception e) {
  
              //br = new BufferedReader( new InputStreamReader( System.in ) );
              in = new Reader();
              out = new PrintWriter( new BufferedWriter(new OutputStreamWriter(System.out)) );
          }
      }
  
      void go() throws Exception {
  
          //int t = in.nextInt();
          int t = 1;
          while (t > 0) {
              solve();
              t--;
          }
  
          out.flush();
          out.close();
      }
  
  
      int inf = 2000000000;
      int mod = 1000000007;
      double eps = 0.000000001;
  
      int n;
      int m;
  
      ArrayList<Integer>[] g;
      int[] a;
  
      void solve() throws IOException {
  
          int n = in.nextInt();
          int[] a = new int[n];
          for (int i = 0; i < n; i++)
              a[i] = in.nextInt();
  
          HashMap<Integer, ArrayList<Pair>> segs = new HashMap<>();
          for (int i = 0; i < n; i++) {
              int sum = 0;
              for (int j = i; j < n; j++) {
                  sum += a[j];
                  if (!segs.containsKey(sum))
                      segs.put(sum, new ArrayList<>());
                  segs.get(sum).add(new Pair(i, j));
              }
          }
  
          int max = 0;
          ArrayList<Pair> ans = new ArrayList<>();
          for (Integer k : segs.keySet()) {
              ArrayList<Pair> list = segs.get(k);
              ArrayList<Pair> blocks = new ArrayList<>();
              Collections.reverse(list);
              int prev = inf;
              for (Pair p : list) {
                  int l = p.a;
                  int r = p.b;
                  if (r < prev) {
                      blocks.add(p);
                      prev = l;
                  }
              }
              if (blocks.size() > max) {
                  ans = blocks;
                  max = blocks.size();
              }
          }
          out.println(ans.size());
          for (Pair p : ans)
              out.println((p.a+1)+" "+(p.b+1));
      }
  
  
      class Pair implements Comparable<Pair>{
  
          int a;
          int b;
  
          Pair(int a, int b) {
  
              this.a = a;
              this.b = b;
          }
  
          public int compareTo(Pair p) {
              if (a != p.a)
                  return Integer.compare(a, p.a);
              else
                  return Integer.compare(b, p.b);
          }
      }
  
      class Item {
  
          int a;
          int b;
          int c;
  
          Item(int a, int b, int c) {
              this.a = a;
              this.b = b;
              this.c = c;
          }
  
      }
  
  
      class Reader {
  
          BufferedReader  br;
          StringTokenizer tok;
  
          Reader(String file) throws IOException {
              br = new BufferedReader( new FileReader(file) );
          }
  
          Reader() throws IOException {
              br = new BufferedReader( new InputStreamReader(System.in) );
          }
  
          String next() throws IOException {
  
              while (tok == null || !tok.hasMoreElements())
                  tok = new StringTokenizer(br.readLine());
              return tok.nextToken();
          }
  
          int nextInt() throws NumberFormatException, IOException {
              return Integer.valueOf(next());
          }
  
          long nextLong() throws NumberFormatException, IOException {
              return Long.valueOf(next());
          }
  
          double nextDouble() throws NumberFormatException, IOException {
              return Double.valueOf(next());
          }
  
  
          String nextLine() throws IOException {
              return br.readLine();
          }
  
      }
  
      static class InputReader
      {
          final private int BUFFER_SIZE = 1 << 16;
          private DataInputStream din;
          private byte[] buffer;
          private int bufferPointer, bytesRead;
  
          public InputReader()
          {
              din = new DataInputStream(System.in);
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
  
          public InputReader(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[64]; // line length
              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();
          }
      }
  
  } 