//DAG模型记忆化搜索
#include<bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
#define F(i,a,b)  for (int i=a;i<b;i++)
#define FF(i,a,b) for (int i=a;i<=b;i++)
#define mes(a,b)  memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
typedef long long ll;
const int N = 1e6+10, M=35;int n,m;
int box[M][M],dp[M],fa[M],vis[M],G[M][M];
bool jBigi(int a,int b)
{FF(i,1,m) if(box[a][i]>=box[b][i]) return false;return true;
}
int D(int x)
{if(vis[x]) return dp[x];vis[x]=1;int &ans=dp[x]=1;FF(i,1,n) if(G[x][i] && ans<D(i)+1) {ans=D(i)+1, fa[x]=i;}return ans;
}
void print_ans(int mi)
{printf("%d\n", dp[mi]);int first=1;while(mi!=-1) {if(!first) printf(" "); first=0;printf("%d", mi);mi=fa[mi];}printf("\n");
}
int main()
{while(~scanf("%d%d", &n,&m)) {FF(i,1,n) {FF(j,1,m) scanf("%d", &box[i][j]);sort(box[i]+1,box[i]+1+m);}mes(G,0);  mes(vis,0);  mes(fa,-1);FF(i,1,n) FF(j,1,n) if(jBigi(i,j)) G[i][j]=1;int maxn=-INF, mi;FF(i,1,n) {dp[i]=D(i);if(maxn<dp[i]) maxn=dp[i], mi=i;}print_ans(mi);}return 0;
}

//最长上升子序列
#include<bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
#define F(i,a,b)  for (int i=a;i<b;i++)
#define FF(i,a,b) for (int i=a;i<=b;i++)
#define mes(a,b)  memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
typedef long long ll;
const long long LINF = 1e18+1LL;
const int N = 1e5+10, M = 35;int dp[M],fa[M],n,m;
struct box
{int di[M],ord;void Sort() { sort(di+1,di+m+1); }friend bool operator < (const box & a, const box & b) {FF(i,1,m) if(a.di[i]>b.di[i]) return false;     //注：这里不能>=，必须>。因为是重载<，要尽可能使a<breturn true;}
}B[M];bool jBigi(int a,int b)
{FF(i,1,m) if(B[a].di[i]>=B[b].di[i]) return false;return true;
}
void print_ans(int mi)
{printf("%d\n", dp[mi]);int first=1;while(mi!=-1) {if(!first) printf(" "); first=0;printf("%d", B[mi].ord);mi=fa[mi];}printf("\n");
}
int main()
{while(~scanf("%d%d", &n,&m)){FF(i,1,n) {FF(j,1,m) scanf("%d", &B[i].di[j]);B[i].Sort(); B[i].ord=i;}sort(B+1,B+1+n);mes(fa,-1);int maxn=-INF, mi;for(int i=n; i>0; --i) { dp[i]=1;for(int j=n; j>i; --j) {if(jBigi(i,j) && dp[i]<dp[j]+1) {dp[i]=dp[j]+1, fa[i]=j;}if(maxn<dp[i]) maxn=dp[i], mi=i;}}print_ans(mi);}return 0;
}