D

#include <array>
#include <iostream>
#include <vector>
#include <stack>
#include <deque>

using namespace std;

#define int long long

const long long INF = 1e18 + 7;
const int MAXN = 2e5 + 10;
const int N = 2e5;

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int n;
    cin >> n;
    deque<int> a(n);
    vector<bool> used1(n + 1), used2(n + 2);
    stack<int> st;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
        used1[a[i]] = true;
    }
    vector<pair<int, int>> ans;
    int cur = 1;
    while (cur <= n) {
        if (used1[cur]) {
            int cnt = 0;
            while (a[0] != cur) {
                st.push(a[0]);
                used1[a[0]] = false;
                used2[a[0]] = true;
                a.pop_front();
                ++cnt;
            }
            st.push(a[0]);
            used1[a[0]] = false;
            used2[a[0]] = true;
            a.pop_front();
            ++cnt;
            ans.emplace_back(1, cnt);
            ans.emplace_back(2, 1);
            st.pop();
            ++cur;
        } else if (used2[cur]) {
            if (st.top() != cur) {
                cout << 0 << '\n';
                return 0;
            }
            ans.emplace_back(2, 1);
            used2[cur] = false;
            st.pop();
            ++cur;
        }
    }
    vector<pair<int, int>> ans1 = {ans[0]};
    for (int i = 1; i < ans.size(); ++i) {
        if (ans1.back().first == ans[i].first) {
            ++ans1.back().second;
        } else {
            ans1.emplace_back(ans[i]);
        }
    }
    for (auto& [x, y]: ans1) {
        cout << x << ' ' << y << '\n';
    }
}