source_code: import java.util.*;
  import java.io.*;
  
  public class SameSumBlock {
  	static BufferedReader br;
  	static StringTokenizer tokenizer;
  
  	public static void main(String[] args) throws Exception {
  		br = new BufferedReader(new InputStreamReader(System.in));
  		int n = nextInt();
  		int[] arr = new int[n];
  		int[] pSum = new int[n];
  		for(int i = 0; i< n; i++) {
  			arr[i] = nextInt();
  			if(i != 0)
  				pSum[i] += pSum[i - 1];
  			pSum[i] += arr[i];
  		}
  		ArrayList<Interval> sorted = new ArrayList<Interval>();
  		for(int i = 0; i < n; i++)
  			sorted.add(new Interval(pSum[i],0, i));
  		for(int i = 1; i < n; i++) {
  			for(int j = i; j < n; j++) {
  				sorted.add(new Interval(pSum[j] - pSum[i - 1], i, j));
  			}
  		}
  		sorted.sort(null);
  		int i = 0;
  		int max = 0, idx = 0, end = 0;
  		while(i < sorted.size()) {
  			int last = i;
  			int curr = 1;
  			int start = i;
  			sorted.get(i).marked = true;
  			while(i < sorted.size() - 1 && sorted.get(i).val == sorted.get(i + 1).val) {
  				i++;
  				if(sorted.get(i).l > sorted.get(last).r) {
  					sorted.get(i).marked = true;
  					curr++;
  					last = i;
  				}
  			}
  			if(curr > max) {
  				max = curr;
  				idx = start;
  				end = i;
  			}
  			i++;
  		}
  		System.out.println(max);
  		for(int j = idx; j <= end; j++) {
  			if(sorted.get(j).marked)
  				System.out.println(sorted.get(j).l + 1 + " " + (sorted.get(j).r + 1));
  		}
  	}
  
  	public static String next() throws IOException {
  		while (tokenizer == null || !tokenizer.hasMoreTokens()) {
  			String line = br.readLine();
  			if (line == null)
  				throw new IOException();
  			tokenizer = new StringTokenizer(line);
  		}
  		return tokenizer.nextToken();
  	}
  
  	public static int nextInt() throws IOException {
  		return Integer.parseInt(next());
  	}
  }
  class Interval implements Comparable<Interval> {
  	int val, l, r;
  	boolean marked;
  	public Interval(int val, int l, int r) {
  		super();
  		this.val = val;
  		this.l = l;
  		this.r = r;
  	}
  
  	@Override
  	public int compareTo(Interval o) {
  		if(val != o.val)
  			return val - o.val;
  		return r - o.r;
  	}
  	
  }