# include <bits/stdc++.h>
# define ll long long
# define ld long double
# define pii pair<int, int>
# define fi first
# define se second
using namespace std;

int main() {
	int N, K;
	scanf("%d %d", &N, &K);
	
	vector<pair<pii, int> > arr(N);
	for(int i=0;i<N;i++) {
		scanf("%d %d", &arr[i].fi.fi, &arr[i].fi.se);
		arr[i].se = i;
	}
	sort(arr.begin(), arr.end());
	priority_queue<int> PQ;
	
	int sp = -1, len = -1;
	for(int c=0;c<arr.size();c++) {
		if(PQ.size() >= K - 1) {
			int st = c, l = min(-PQ.top(), arr[c].fi.se) - arr[c].fi.fi;
			l = max(l, 0);
			if(l >= len) {
				len = l;
				sp = st;
			}
		}
		PQ.push(-arr[c].fi.se);
		if(PQ.size() > K - 1) PQ.pop();
	}
	
	printf("%d\n", len);
	
	vector<int> ans;
	ans.clear();
	
	priority_queue<pii> P;
	
	for(int c=0;c<sp;c++) {
		P.push({-arr[c].fi.se, arr[c].se});
		if(P.size() > K - 1) P.pop();
	}
	ans.push_back(arr[sp].se);
	while(P.size()) {
		ans.push_back(P.top().se);
		P.pop();
	}
	sort(ans.begin(), ans.end());
	for(auto p : ans) printf("%d ", p + 1);
	printf("\n");
	
}