source_code: import java.util.HashMap;
  import java.util.Scanner;
  
  public class Main{
  	
  	int[] ints;
  	int[] prefix;
  	
  	public static void main(String[] args)
  	{
  		new Main().run();
  	}
  	
  	public void run()
  	{
  		Scanner file = new Scanner(System.in);
  		int N = file.nextInt();
  		ints = new int[N];
  		for(int i = 0;i<N;i++)
  			ints[i] = file.nextInt();
  		prefix = new int[N];
  		prefix[0] = ints[0];
  		for(int i =1;i<prefix.length;i++)
  			prefix[i] = prefix[i-1]+ints[i];
  		HashMap<Integer,Integer> ending = new HashMap<>();//ending for each sum
  		HashMap<Integer,Integer> amount = new HashMap<>();//k for each sum
  		for(int end = 0;end<prefix.length;end++)
  		{
  			for(int start = 0;start<=end;start++)
  			{
  				int sum = sum(start,end);
  				if(!ending.containsKey(sum))
  					ending.put(sum, -1);
  				if(!amount.containsKey(sum))
  					amount.put(sum,0);
  				if(ending.get(sum)<start)
  				{
  					amount.put(sum,amount.get(sum)+1);
  					ending.put(sum,end);
  				}
  			}
  		}
  		int max = 0;
  		int maxnum = -1;
  		for(int x:amount.keySet())
  		{
  			if(amount.get(x)>max)
  			{
  				max = amount.get(x);
  				maxnum = x;
  			}
  		}
  		System.out.println(max);
  		HashMap<Integer,Integer> occurrence = new HashMap<Integer,Integer>();
  		occurrence.put(0,0);
  		for(int i = 0;i<prefix.length;i++)
  		{
  			if(occurrence.containsKey(prefix[i]-maxnum))
  			{
  				System.out.println(occurrence.get(prefix[i]-maxnum)+1+" "+(i+1));
  				occurrence.clear();
  			}
  			occurrence.put(prefix[i],i+1);
  		}
  	}
  	
  	public int sum(int L, int R)
  	{
  		return prefix[R] - prefix[L] + ints[L];
  	}
  	
  }
  