#include <iostream>
#include <algorithm> // for sort, mainly
#include <vector>
#include <map>
#include <set>
#include <cmath>
#include <array>
#include <string>
#include <cstdio>
#include <iterator>
#include <unordered_set>
#include <cstdint> // for int64_t, int32_t, etc
#include <queue>
#include <stack>
#include <deque>
#include <numeric> // gcd, lcm
#include <fstream>
#include <bitset> // for bitset
#include <iomanip>
#include <cassert> // for set with custom ordering
#include <type_traits> // for set with custom ordering
#include <utility> // for swap, forward, etc
using namespace std;

#pragma GCC optimize("O2")
// #pragma GCC optimize("O1","O2","O3","Ofast","unroll-loops")
//#pragma GCC target("sse","sse2","sse3","sse4.1","sse4.2","avx","avx2","fma")

template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
void dbg_out() { cout << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cout << ' ' << H; dbg_out(T...); }
#ifdef LOCAL
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

/*
 *
 * notes:
 *
 * int64_t
 * stoi(string s) -> string to int
 * to_string() -> int (or else) to string
 *
 * vector declaration:
 * vector<ll> v(n, 0)
 * vector<vector<ll>> v(n, vector<ll>(n, 0));
 *
 * {if statement} ? {truth value} : {false value}
 *
 * set lower bound/upper bound:
 * 	// . . . m1 . . . d . . . . m2
 *    auto m1_it = b.lower_bound(d);
 *    advance(m1_it, -1);
 *    m1 = *m1_it;
 *	m2 = *b.upper_bound(d);
 *
 * #ifdef LOCAL
 *    freopen("in.txt","r",stdin);
 *    freopen("out.txt","w",stdout);
 * #endif
 *
 * constexpr auto lcm(auto x, auto... xs)
 * {
 *	return ((x = std::lcm(x, xs)), ...);
 * }
 *
 * std::gcd(int a, int b)
 *
 * cout << setprecision(n);
 *
 * set with custom ordering
 * set<ll, decltype(&cmp)> qu(cmp);
 *
 */

typedef int64_t ll;

vector<string> ans;

void check(ll len, vector<ll> &v, ll n) {

    if(len == 1) {
        return;
    }

    // meg lehet-e ugy csinalni
    // hogy len darab egymas melletti pont legyen egy szakaszban
    // megnezzuk az osszes szakasz hosszat
    // es megnezzuk, hogy a leghosszabb szakasz hosszat veve
    // a tobbit is meg lehet-e csinalni
    // ha igen, jo
    // ha nem, ugyis jo

    //cerr << "\nlen=" << len;

    ll segcount = n / len;

    ll seglen = 0;

    for(ll i = 0; i < n; i += len) {

        //cerr << "\ni=" << i;

        ll segstart = v[i];
        ll segend = v[i+len - 1];

        //cerr << "\nsegstart=" << segstart << "; segend=" << segend; 
        seglen = max(seglen, segend - segstart);
    }

    //cerr << "\nseglen=" << seglen;

    vector<ll> segstart(segcount, 0);
    for(ll i = 0; i < segcount; i++) {
        
        ll ssid = i * len; // seg-start id

        if(i == 0) {
            // ez mindig lehetseges
            segstart[i] = v[ssid + len - 1] - seglen;
        }else if(i == segcount -1) {
            // ez mindig lehetseges
            segstart[i] = v[ssid];
        }else{
            // olyan elol kezdjuk amennyire csak lehet
            ll hs = segstart[i-1] + seglen + 1; // earliest possible start is the end of the previous segment+1
            ll minstart = v[ssid+len-1] - seglen;

            //cerr << "\ni=" << i << "; hs=" << hs << "; minstart=" << minstart;

            ll start = max(hs, minstart);

            //cerr << "\nstart=" << start << "; end=" << start + seglen;

            if(start + seglen >= v[ssid+len]) {
                return;
            }
            segstart[i] = start;
        }
    }

    string h = to_string(segcount) + " " + to_string(seglen) + "\n";
    for(const auto & x : segstart) {
        h += to_string(x) + "\n";
    }

    ans.push_back(h);

}

void solve() {

    // az n minden osztolyat meg kell nezzuk
    ll n;
    cin >> n;

    vector<ll> v(n, 0);
    for(ll i = 0; i < n; i++) {
        cin >> v[i];
    }

    for(ll i = 1; i * i <= n; i++) {

        if(n % i == 0) {

            ll a = n / i;
            ll b = i;

            if(a == b) {
                check(a, v, n);
            }else{
                check(a, v, n);
                check(b, v, n);
            }

        }
    }

    cout << ans.size() << "\n";
    for(const auto & x : ans) {
        cout << x;
    }

}

int main()
{
    std::ios_base::sync_with_stdio(false);
    //cin.tie(nullptr);
    //cout.tie(nullptr);

    solve();

    return 0;
}