#include <fstream>
#include <vector>

using namespace std;

ifstream cin("scmax.in");
ofstream cout("scmax.out");

const int INF = 1e9;

void get_sol(int i, vector < int > &prev, vector < int > &elem) {

  if (i == 0) {
    return;
  }

  get_sol(prev[i], prev, elem);
  cout << elem[i] << ' ';
}

int main() {

  int n;
  cin >> n;

  vector < int > dp(n + 1);
  vector < int > prev(n + 1);
  vector < int > elem(n + 1);

  dp[0] = 0;
  elem[0] = -INF;
  int last = 0;
  for (int i = 1; i <= n; i ++) {
    cin >> elem[i];

    if (elem[i] > elem[dp[last]]) {
      dp[++ last] = i;
      prev[i] = dp[last - 1];
      cout << elem[i] << ' ' << last << '\n';
    }
    else {

      int st = 1;
      int dr = last;
      while (st <= dr) {

        int mid = (st + dr) >> 1;
        if (elem[dp[mid]] < elem[i]) {
          st = mid + 1;
          continue;
        }
        dr = mid - 1;
      }

      cout << elem[i] << ' ' << st << '\n';
      dp[st] = i;
      prev[i] = dp[st - 1];
    }
  }

  cout << last << '\n';
  get_sol(dp[last], prev, elem);
  cout << '\n';
}