#include<bits/stdc++.h>

 #define lowbit(x) x&(-x)

 #define LL long long

 #define N 100005

 #define M 1000005

 #define mod 2147483648LL

 #define inf 0x7ffffffff

 using namespace std;

 inline int ra()

 {

     int x=,f=; char ch=getchar();

     while (ch<'' || ch>''){if (ch=='-') f=-; ch=getchar();}

     while (ch>='' && ch<=''){x=x*+ch-''; ch=getchar();}

     return x*f;

 }

 int n,k;

 struct node{

     int x,y,id;

 }a[N<<];

 bool cmp(node a, node b)

 {

     if (a.x==b.x) return a.y<b.y;

     return a.x<b.x;

 }

 int ans,cnt;

 int b[N<<],L,R;

 set<pair<int , int > > q;

 set<pair<int , int > >:: iterator it;

 int main()

 {

     n=ra(); k=ra();

     for (int i=; i<=n; i++)

         a[i].x=ra(),a[i].y=ra(),a[i].id=i;

     sort(a+,a+n+,cmp);

     if (n==)//zz

     {

         cout<<a[].y-a[].x+<<endl;

         cout<<"";

         return ;

     }

 //    for (int i=1; i<=n; i++)

 //        printf("%d %d %d\n",a[i].x,a[i].y,a[i].id);

     q.insert(make_pair(a[].y,a[].id));

     for (int i=; i<=n; i++)

     {

         pair<int , int > tmp,qwq;

         tmp=*q.begin();

         while (a[i].x>tmp.first && !q.empty())

         {

             q.erase(tmp);

             tmp=*q.begin();

         }

         q.insert(make_pair(a[i].y,a[i].id));

         if (q.size()>=k)

         {

             tmp=*q.begin();

             if (ans<tmp.first-a[i].x+)

             {

                 cnt=;

                 ans=tmp.first-a[i].x+;

                 L=a[i].x;

                 R=tmp.first;

             }

             q.erase(tmp); //这里比较有意思，这是最小的，只要记录的最小的是没有用了的，再加着反而会让结果变小

         }

     }

     cout<<ans<<endl;

     if (ans==)

     {

         for (int i=; i<=k; i++) cout<<i<<" ";

     }

     else

     {

         //cout<<L<<" "<<R<<endl;

         for (int i=; i<=n; i++)

             if (L>=a[i].x && R<=a[i].y && k)    //tmd还能这么输出，真是尴尬啊、、、

                 cout<<a[i].id<<" ",k--;

     }

     return ;

 }

 //%%%%%%%%%%%%%%%%cf有数据就是好，面相数据编程233