//

 //by coolxxx

 //#include<bits/stdc++.h>

 #include<iostream>

 #include<algorithm>

 #include<string>

 #include<iomanip>

 #include<map>

 #include<stack>

 #include<queue>

 #include<set>

 #include<bitset>

 #include<memory.h>

 #include<time.h>

 #include<stdio.h>

 #include<stdlib.h>

 #include<string.h>

 //#include<stdbool.h>

 #include<math.h>

 #define min(a,b) ((a)<(b)?(a):(b))

 #define max(a,b) ((a)>(b)?(a):(b))

 #define abs(a) ((a)>0?(a):(-(a)))

 #define lowbit(a) (a&(-a))

 #define sqr(a) ((a)*(a))

 #define swap(a,b) ((a)^=(b),(b)^=(a),(a)^=(b))

 #define mem(a,b) memset(a,b,sizeof(a))

 #define eps (1e-8)

 #define J 10

 #define mod 1000000007

 #define MAX 0x7f7f7f7f

 #define PI 3.14159265358979323

 #define N 104

 using namespace std;

 typedef long long LL;

 int cas,cass;

 int n,m,lll,ans;

 int a[N][N];

 int sum,total;

 int main()

 {

 //    freopen("easy.in","r",stdin);

 //    freopen("easy.out","w",stdout);

     int i,j,k;

 //    for(scanf("%d",&cass);cass;cass--)

 //    for(scanf("%d",&cas),cass=1;cass<=cas;cass++)

 //    while(~scanf("%s",s+1))

     while(~scanf("%d",&n))

     {

         mem(a,);sum=,total=;

         scanf("%d",&m);

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

         {

             scanf("%d",&a[i][]);

             for(j=;j<=a[i][];j++)

             {

                 scanf("%d",&a[i][j]);

             }

         }

         for(j=;j<= && total!=m;j++)

         {

             for(i=;i<=n && total!=m;i++)

             {

                 if(j>a[i][])

                 {

                     sum+=;

                     total++;

                     continue;

                 }

                 if(a[i][j]>=sum)

                 {

                     sum+=a[i][j];

                     total++;

                 }

             }

         }

         if(total<m)

             sum+=*(m-total);

         printf("%d\n",sum);

     }

     return ;

 }

 /*

 //

 //

 */