#include <bits/stdc++.h>

using namespace std;

#define i32 int32_t
#define i64 int64_t

static constexpr i32 MAX = 1'000'000;

int main() {
#ifndef LOCAL
  freopen("huffman.in", "r", stdin);
  freopen("huffman.out", "w", stdout);
#endif
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  struct Node {
    i64 v{};
    i32 next[2]{};
  };
  static Node tree[2 * MAX + 5];
  i32 N;
  if (!(cin >> N)) {
    return 1;
  }
  if (N == 1) {
    i64 x;
    if (!(cin >> x)) {
      return 1;
    }
    cout << 0 << '\n' << 1 << ' ' << 0 << '\n';
    return 0;
  }
  for (i32 i = 1; i <= N; ++i) {
    if (!(cin >> tree[i].v)) {
      return 1;
    }
  }
  i64 X = 0;
  vector<i32> Q1(N + 2);
  for (i32 i = 1; i <= N; ++i) {
    Q1[i] = i;
  }
  i32 L1 = 1, R1 = N;
  vector<i32> Q2(N + 2);
  i32 L2 = 1, R2 = 0;
  i32 nextIdx = N;
  for (; (R1 - L1 + 1) + (R2 - L2 + 1) > 1;) {
    ++nextIdx;
    tree[nextIdx].v = 0;
    for (int j = 0; j < 2; ++j) {
      i32 pick;
      if (L1 <= R1 && (L2 > R2 || tree[Q1[L1]].v <= tree[Q2[L2]].v)) {
        pick = Q1[L1++];
      } else {
        pick = Q2[L2++];
      }
      tree[nextIdx].next[j] = pick;
      tree[nextIdx].v += tree[pick].v;
    }
    Q2[++R2] = nextIdx;
    X += tree[nextIdx].v;
  }
  i32 root = Q2[R2];
  vector<i32> L(N + 1);
  vector<i64> B(N + 1);
  auto dfs = [&](auto self, i32 i, i64 x, i32 h) -> void {
    if (tree[i].next[0] || tree[i].next[1]) {
      self(self, tree[i].next[0], x << 1, h + 1);
      self(self, tree[i].next[1], (x << 1) | 1, h + 1);
    } else if (i <= N) {
      L[i] = h;
      B[i] = x;
    }
  };
  dfs(dfs, root, 0, 0);
  cout << X << '\n';
  for (i32 i = 1; i <= N; ++i) {
    cout << L[i] << ' ' << B[i] << '\n';
  }
  return 0;
}