#include <bits/stdc++.h>
using namespace std;
const int NMAX = 300000;
pair<int, int> intv[NMAX];
int normalized[NMAX];
int mapFromNormalized[NMAX];
int idx[NMAX];
struct FenwickTree {
  vector<int> tree;
  FenwickTree() {}
  FenwickTree(const int& _n) : tree(vector<int>(_n + 1)) {}
  void update(int idx) {
    idx++;
    while (idx < ((int)(tree).size())) {
      tree[idx]++;
      idx += (idx & -idx);
    }
  }
  int query(int k) const {
    int pos = 0;
    for (int step = 1 << 19; step; step >>= 1) {
      if (pos + step < ((int)(tree).size()) and tree[pos + step] <= k) {
        k -= tree[pos + step];
        pos += step;
      }
    }
    return pos + 1;
  }
};
int main(void) {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  int n, k;
  cin >> n >> k;
  vector<int> allEnds;
  allEnds.reserve(n);
  for (int i = 0; i < n; i++) {
    cin >> intv[i].first >> intv[i].second;
    allEnds.emplace_back(intv[i].second);
  }
  sort(allEnds.begin(), allEnds.end());
  allEnds.erase(unique(allEnds.begin(), allEnds.end()), allEnds.end());
  allEnds.shrink_to_fit();
  for (int i = 0; i < n; i++) {
    normalized[i] =
        lower_bound(allEnds.begin(), allEnds.end(), intv[i].second) -
        allEnds.begin();
    mapFromNormalized[normalized[i]] = intv[i].second;
  }
  iota(idx, idx + n, 0);
  sort(idx, idx + n,
       [](const int& x, const int& y) { return intv[x] < intv[y]; });
  FenwickTree tree(((int)(allEnds).size()));
  int best = 0, bestIdx = -1, bestRightAnswer;
  for (int i = 0; i < n;) {
    int j = i;
    while (j < n and intv[idx[j]].first == intv[idx[i]].first) {
      tree.update(((int)(allEnds).size()) - normalized[idx[j]] - 1);
      j++;
    }
    if (j >= k) {
      const int bestRight =
          mapFromNormalized[((int)(allEnds).size()) - tree.query(k - 1)];
      const int queryAnswer = bestRight - intv[idx[i]].first + 1;
      if (queryAnswer > best) {
        bestIdx = j;
        best = queryAnswer;
        bestRightAnswer = bestRight;
      }
    }
    i = j;
  }
  if (best == 0) {
    cout << "0\n";
    for (int i = 0; i < k; i++) {
      cout << (1 + i) << ' ';
    }
    cout << '\n';
    return 0;
  }
  cout << best << '\n';
  for (int i = 0; i < bestIdx; i++) {
    if (intv[idx[i]].second >= bestRightAnswer) {
      cout << idx[i] + 1;
      k--;
      if (k == 0) {
        cout << '\n';
        break;
      } else {
        cout << ' ';
      }
    }
  }
}
