#include <bits/stdc++.h>
using namespace std;
#define N (200000)
struct Node{
int a[3];
Node(){}
Node(int x, int y, int z){a[0]=x;a[1]=y;a[2]=z;}
};
int ctl, tree[8*N], dp[N], n;;
int cmp(Node x, Node y){return x.a[ctl] < y.a[ctl];}
Node f[N], tmp1[N], tmp2[N];
vector<int> v;
void push(int x, int pos, int L, int R, int val){
if(pos < L || pos > R)return;
if(pos == L && pos == R){
tree[x] = val;
return;
}
int mid = (L+R)/2;
push(2*x, pos, L, mid, val);
push(2*x+1, pos, mid+1, R, val);
tree[x] = max(tree[x*2], tree[2*x+1]);
return;
}
int get(int x, int l, int r, int L, int R){
if(l > R || r < L)return 0;
if(l <= L && R <= r)return tree[x];
int mid = (L + R) / 2;
return max(get(2*x, l, r, L, mid), get(2*x+1, l, r, mid+1, R));
}
void solve(int l, int r){
if(l == r){dp[l]++;return;}
int mid = (l+r)/2;
solve(l, mid);
for(int i=l; i<=mid; i++)tmp1[i] = f[i], tmp1[i].a[0]=i;
for(int i=mid+1; i<=r; i++)tmp2[i] = f[i], tmp2[i].a[0]=i;
sort(tmp1+l, tmp1+mid+1, cmp);
sort(tmp2+mid+1, tmp2+r+1, cmp);
int ll=l, rr=mid+1;
while(ll < mid+1 || rr <= r){
if(ll < mid+1 && tmp1[ll].a[1] < tmp2[rr].a[1] || rr > r){
push(1, tmp1[ll].a[2], 0, n-1, dp[tmp1[ll].a[0]]);
ll++;
}
else{
dp[tmp2[rr].a[0]] = max(get(1, 0, tmp2[rr].a[2]-1, 0, n-1), dp[tmp2[rr].a[0]]);
rr++;
}
}
for(int i=l; i<=mid; i++)push(1, tmp1[i].a[2], 0, n-1, 0);
solve(mid+1, r);
}
int main(){
int m,ans=0;
scanf("%d %d", &m, &n);
for(int i=0; i<m; i++)for(int j=0; j<n; j++)scanf("%d", &f[j].a[i]);
sort(f, f+n, cmp);
if(m == 2){
v.push_back(0);
for(int i=0; i<n; i++){
auto it = lower_bound(v.begin(), v.end(), f[i].a[1]);
if(it == v.end())v.push_back(f[i].a[1]);
else *it = f[i].a[1];
}
printf("%d\n", v.size()-1);
}
else{
ctl=1;
for(int idx=1; idx<3; idx++){
map<int, int> mp;
for(int i=0; i<n; i++)mp[f[i].a[idx]]=0;
int a = 0;
for(auto it=mp.begin(); it != mp.end(); it++)it->second=a++;
for(int i=0; i<n; i++)f[i].a[idx] = mp[f[i].a[idx]];
}
solve(0, n-1);
for(int i=0; i<n; i++)ans=max(ans, dp[i]);
printf("%d\n", ans);
}
return 0;
}
