#include <bits/stdc++.h>
using namespace std;
const int N = 5005;
int n, q, B, ind, a[N], aa[N];
vector<vector<int> > f[N];
int nid;
vector<int> pos[260], res;
vector<pair<int, int> > ans;
int mer(int k1, int k2) {
  if (!k1 || !k2) return k1 + k2;
  ans.push_back(make_pair(k1, k2));
  return ++ind;
}
vector<vector<int> > bud(int l, int r, vector<int> npos) {
  if (l == r) {
    return {{npos[0]}};
  }
  int mid = (l + r) >> 1;
  vector<int> posl, posr;
  for (auto x : npos) (a[x] <= mid ? posl : posr).push_back(x);
  auto resl = bud(l, mid, posl), resr = bud(mid + 1, r, posr),
       res = vector<vector<int> >(r - l + 1, vector<int>(r - l + 1));
  for (int i = (0); i <= (((int)(npos).size()) - 1); ++i)
    for (int j = (i); j <= (((int)(npos).size()) - 1); ++j) {
      int L = lower_bound((posl).begin(), (posl).end(), npos[i]) - posl.begin();
      int R =
          upper_bound((posl).begin(), (posl).end(), npos[j]) - posl.begin() - 1;
      int& t = res[i][j];
      t = 0;
      if (L <= R) {
        t = resl[L][R];
      }
      L = lower_bound((posr).begin(), (posr).end(), npos[i]) - posr.begin();
      R = upper_bound((posr).begin(), (posr).end(), npos[j]) - posr.begin() - 1;
      if (L <= R) {
        t = mer(t, resr[L][R]);
      }
    }
  return res;
}
void sol(int L, int R) {
  pos[nid].clear();
  for (int i = (L); i <= (R); ++i) pos[nid].push_back(aa[i]);
  sort((pos[nid]).begin(), (pos[nid]).end());
  f[nid] = bud(L, R, pos[nid]);
}
int main() {
  scanf("%d%d", &n, &q);
  B = 1 << 8;
  for (int i = (1); i <= (n); ++i) scanf("%d", a + i), aa[a[i]] = i;
  nid = 1, ind = n;
  for (int i = 1; i <= n; i += B) {
    sol(i, min(n, i + B - 1));
    ++nid;
  }
  while (q--) {
    int l, r;
    scanf("%d%d", &l, &r);
    nid = 0;
    int now = 0;
    for (int i = 1; i <= n; i += B) {
      ++nid;
      auto L = lower_bound((pos[nid]).begin(), (pos[nid]).end(), l) -
               pos[nid].begin();
      auto R = upper_bound((pos[nid]).begin(), (pos[nid]).end(), r) -
               pos[nid].begin() - 1;
      if (L <= R) {
        now = mer(now, f[nid][L][R]);
      }
    }
    res.push_back(now);
  }
  printf("%d\n", ((int)(ans).size()) + n);
  for (auto x : ans) printf("%d %d\n", x.first, x.second);
  for (auto x : res) printf("%d ", x);
  return 0;
}
