#include <bits/stdc++.h>
using namespace std;
int a[1500];
int S[1501];
int dp[1501];
int p[1501];
int n;
map<int, vector<int>> all;
int get(int x) {
  int l = 0;
  int r = 0;
  int c = 0;
  dp[0] = 0;
  for (r = 0; r < n; ++r) {
    dp[r + 1] = dp[r];
    p[r + 1] = r;
    int xx = S[r + 1] - x;
    if (all.count(xx)) {
      const vector<int> &v = all[xx];
      int L = -1;
      int R = v.size();
      while (R - L > 1) {
        int C = (L + R) / 2;
        if (v[C] >= r + 1)
          R = C;
        else
          L = C;
      }
      if (L >= 0 && L < v.size() && v[L] < r + 1) {
        while (L >= 0) {
          if (dp[r + 1] < dp[v[L]] + 1) {
            dp[r + 1] = dp[v[L]] + 1;
            p[r + 1] = v[L];
          }
          --L;
        }
      }
    }
  }
  return dp[n];
}
void solve() {
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) scanf("%d", &a[i]);
  S[0] = 0;
  for (int i = 0; i < n; ++i) {
    S[i + 1] = S[i] + a[i];
  }
  for (int i = 0; i < n + 1; ++i) {
    all[S[i]].push_back(i);
  }
  set<int> was;
  vector<pair<int, int>> res;
  int best = 0;
  int bestc = 0;
  for (int i = 0; i < n; ++i) {
    int s = 0;
    for (int j = i; j < n; ++j) {
      s += a[j];
      if (!was.count(s)) {
        was.insert(s);
        int c = get(s);
        if (bestc < c) {
          bestc = c;
          best = s;
        }
      }
    }
  }
  get(best);
  printf("%d\n", dp[n]);
  int x = n;
  while (x != 0) {
    int pp = p[x];
    if (dp[pp] != dp[x]) {
      printf("%d %d\n", pp + 1, x);
    }
    x = pp;
  }
}
int main() {
  solve();
  return 0;
}
