source_code: import java.io.*;
  import java.util.*;
  
  public class CF1141F {
  	static class V {
  		int l, r, a;
  		V(int l, int r, int a) {
  			this.l = l; this.r = r; this.a = a;
  		}
  	}
  	public static void main(String[] args) throws IOException {
  		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  		PrintWriter pw = new PrintWriter(System.out);
  		int n = Integer.parseInt(br.readLine());
  		StringTokenizer st = new StringTokenizer(br.readLine());
  		int[] aa = new int[n + 1];
  		for (int i = 1; i <= n; i++)
  			aa[i] = Integer.parseInt(st.nextToken());
  		for (int i = 1; i <= n; i++)
  			aa[i] += aa[i - 1];
  		int m = n * (n + 1) / 2;
  		V[] vv = new V[m];
  		m = 0;
  		for (int i = 1; i <= n; i++)
  			for (int j = i; j <= n; j++)
  				vv[m++] = new V(i, j, aa[j] - aa[i - 1]);
  		Arrays.sort(vv, (u, v) -> u.a != v.a ? u.a - v.a : u.r - v.r);
  		int[] ii_ = new int[m];
  		int[] ii = new int[m];
  		int k_ = 0;
  		for (int i = 0, j; i < m; i = j) {
  			j = i + 1;
  			while (j < m && vv[j].a == vv[i].a)
  				j++;
  			int k = 0, r = 0;
  			for (int h = i; h < j; h++)
  				if (vv[h].l > r) {
  					ii[k++] = h;
  					r = vv[h].r;
  				}
  			if (k_ < k) {
  				k_ = k;
  				int[] tmp = ii_; ii_ = ii; ii = tmp;
  			}
  		}
  		pw.println(k_);
  		for (int h = 0; h < k_; h++) {
  			int i = ii_[h];
  			pw.println(vv[i].l + " " + vv[i].r);
  		}
  		pw.close();
  	}
  }
  