#include <bits/stdc++.h>
using namespace std;
template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
  for (auto& i : v) is >> i;
  return is;
}
template <typename T>
ostream& operator<<(ostream& os, vector<T> v) {
  for (auto& i : v) os << i << '\n';
  return os;
}
inline uint64_t modpow(uint64_t base, uint64_t exp, uint64_t modulus) {
  base %= modulus;
  uint64_t result = 1;
  while (exp > 0) {
    if (exp & 1) result = (result * base) % modulus;
    base = (base * base) % modulus;
    exp >>= 1;
  }
  return result;
}
void solve() {
  int n;
  cin >> n;
  vector<int> a(n);
  cin >> a;
  vector<vector<int>> v(n, vector<int>(n));
  for (int j = 0; j < n; j++) {
    int sum = 0;
    for (int i = j; i >= 0; i--) {
      sum += a[i];
      v[i][j] = sum;
    }
  }
  map<int, vector<pair<int, int>>> last;
  map<int, int> cnt;
  for (int j = 0; j < n; j++) {
    for (int i = 0; i <= j; i++) {
      auto it = last.find(v[i][j]);
      if (it != last.end()) {
        if (i > it->second.back().second) {
          cnt[v[i][j]]++;
          last[v[i][j]].push_back({i, j});
        }
      } else {
        cnt[v[i][j]]++;
        last[v[i][j]].push_back({i, j});
      }
    }
  }
  int maxi = 0;
  int maxv = 0;
  for (auto& p : cnt) {
    if (maxv < p.second) {
      maxv = p.second;
      maxi = p.first;
    }
  }
  cout << maxv << "\n";
  for (auto& e : last[maxi]) {
    cout << e.first + 1 << " " << e.second + 1 << "\n";
  }
};
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
