#include <iostream>
#include <queue>
#include <algorithm>
#include <stdio.h>
using namespace std;

const int Maxn = 2147483647;

struct Node{
	int l,r;
	int i;
}node[300010];

bool cmp( const Node &a,const Node &b ){
	return ( a.l == b.l ? a.r < b.r:a.l < b.l );
}

int main(){
	int m,n;
	scanf("%d%d",&m,&n);
	for( int i = 1; i <= m; i++ ){
		scanf("%d%d",&node[i].l,&node[i].r);
		node[i].i = i;
	}
	sort( node+1,node+1+m,cmp );
	priority_queue<int,vector<int>,greater<int> > q;
	int inf = -Maxn;
	int x;
	int l,r;
	for( int i = 1; i <= m; i++ ){
		x = node[i].l;
		q.push( node[i].r );
		while( q.top() < x || q.size() > n ){
			q.pop();
		}
		if( q.size() == n ){
			if( inf < q.top() - x + 1 ){
				inf = q.top() - x + 1;
				l = x,r = q.top();
			}
		}
	}
	if( inf == - Maxn ){
		cout << '0' << endl;
		for( int i = 1; i <= n; i++ ){
			printf( "%d ",i );
		}
		printf( "\n" );
		exit(0);
	}else{
		cout << inf << endl;
		for( int i = 1; i <= m; i++ ){
			if( node[i].l <= l && node[i].r >= r ){
				printf("%d ",node[i].i);
				n--;
				if( n == 0 ){
					cout << '\n';
					exit(0);
				}
			}
		}
	}
}