#include <bits/stdc++.h>

#define x first
#define y second
#define int long long

using namespace std;

const int N = 1e5 + 10;

int n;
int a[N];
map<int, int> hash1;
int idx;
pair<int, int> ans[N];

signed main()
{
    cin >> n;
    for(int i = 1 ; i <= n ; i ++ ) cin >> a[i];
    for(int i = 1 ; i <= n ; i ++ ) hash1[a[i]] = i;
    for(int i = 1 ; i <= n ; i ++ )
        if(a[i] != i)
        {
            int l = i;
            int r = hash1[i];
            for(int j = l ; j <= (r + l) / 2 ; j ++ ) swap(a[j], a[r - j + l]);
            for(int j = l ; j <= r ; j ++ ) hash1[a[i]] = i;
            ans[ ++ idx] = {l, r};
        }
    cout << idx << endl;
    for(int i = 1 ; i <= idx ; i ++ ) cout << ans[i].x << " " << ans[i].y << endl;
    return 0;
}