#include <bits/stdc++.h>
using namespace std;
const int inf = 0x20202020;
const int mod = 1000000007;
template <class T>
inline void read(T& x) {
  bool fu = 0;
  char c;
  for (c = getchar(); c <= 32; c = getchar())
    ;
  if (c == '-') fu = 1, c = getchar();
  for (x = 0; c > 32; c = getchar()) x = x * 10 + c - '0';
  if (fu) x = -x;
};
template <class T>
inline void read(T& x, T& y) {
  read(x);
  read(y);
}
template <class T>
inline void read(T& x, T& y, T& z) {
  read(x);
  read(y);
  read(z);
}
template <class T>
inline void read(T& x, T& y, T& z, T& q) {
  read(x);
  read(y);
  read(z);
  read(q);
}
const int DX[] = {1, 0, -1, 0}, DY[] = {0, 1, 0, -1};
long long powmod(long long a, long long b) {
  long long res = 1;
  a %= mod;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long powmod(long long a, long long b, long long mod) {
  long long res = 1;
  a %= mod;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
const int N = 111111, M = 111111;
int l, m, n, t, C, a[N], b[N];
pair<int, int> res[9];
int calc() {
  int ans = 0;
  for (int _tmp = (n - 1), i = 1; i <= _tmp; ++i) b[i] = a[i + 1] - a[i];
  b[0] = b[1];
  for (int _tmp = (n - 1), i = 1; i <= _tmp; ++i)
    if (b[i] == b[i - 1] && abs(b[i]) == 1)
      ;
    else
      b[i] = b[i + 1], ++ans;
  return ans;
}
void rev(int l, int r) {
  for (int _tmp = (l + r >> 1), i = l; i <= _tmp; ++i) swap(a[i], a[r + l - i]);
}
int ok() {
  for (int _tmp = (n), i = 1; i <= _tmp; ++i)
    if (a[i] != i) return 0;
  return 1;
}
void dfs(int x) {
  if (ok()) {
    printf("%d\n", x - 1);
    for (int _tmp = 1, i = x - 1; i >= _tmp; --i)
      printf("%d %d\n", res[i].first, res[i].second);
    exit(0);
  }
  if (x > 3) return;
  int p = calc();
  for (int _tmp = (n), i = 1; i <= _tmp; ++i)
    for (int _tmp = (n), j = i + 1; j <= _tmp; ++j)
      if (abs(a[i - 1] - a[j]) == 1 || abs(a[i] - a[j + 1]) == 1) {
        rev(i, j);
        int t = calc();
        if (t <= (3 - x) * 2 && t <= p) {
          res[x].first = i;
          res[x].second = j;
          dfs(x + 1);
        }
        rev(i, j);
      }
}
int main() {
  scanf("%d", &n);
  for (int _tmp = (n), i = 1; i <= _tmp; ++i) scanf("%d", &a[i]);
  a[0] = 0;
  a[n + 1] = n + 1;
  dfs(1);
  return 0;
}
