#include <bits/stdc++.h>
#define ROOT 450
using namespace std;
using pr = pair<int, int>;
using tr = pair<int, pr>;
using ll = long long;
// Fast IO
static char _buffer[131072];
static int _currentChar = 0;
static int _charsNumber = 0;
static inline int _read() {
if(_currentChar == 131072) {
_charsNumber = fread(_buffer, 1, 131072, stdin);
_currentChar = 0;
}
return _buffer[_currentChar++];
}
int _c, _t;
static inline int s() {
_c = _read();
while(_c <= 32) _c = _read();
_t = 0;
while(_c > 32) {
_t *= 10;
_t += _c-'0';
_c = _read();
}
return _t;
}
int R, N, ans;
pr A[200005];
tr B[200005];
vector<int> v;
int comp[200005];
vector<int> comp2[ROOT];
struct seg_tree {
int tree[ROOT*4], base;
void init(int x) { for(base=1; base<x; base<<=1); for(int i=1; i<=base*2; i++) tree[i] = 0; }
void update(int x, int y) {
x += base - 1;
tree[x] = y;
while(x / 2) {
if(max(tree[x/2*2], tree[x/2*2+1]) != tree[x]) break;
tree[x/2] = tree[x];
x /= 2;
}
}
int RMQ(int s, int e) {
s += base - 1, e += base - 1;
int res = 0;
while(s < e) {
if(s & 1) res = max(res, tree[s++]);
if(!(e & 1)) res = max(res, tree[e--]);
s >>= 1, e >>= 1;
}
if(s == e) res = max(res, tree[s]);
return res;
}
} S[ROOT];
vector<tr> bucket[ROOT];
int main() {
R = s(), N = s();
if(R == 2) {
for(int i=1; i<=N; i++) A[i].first = s();
for(int i=1; i<=N; i++) A[i].second = s();
sort(A+1, A+N+1);
for(int i=1; i<=N; i++) {
auto it = lower_bound(v.begin(), v.end(), A[i].second);
if(it == v.end()) v.push_back(A[i].second);
else *it = A[i].second;
}
printf("%d\n", v.size());
}
else {
for(int i=0; i<=N/ROOT; i++) S[i].init(ROOT);
for(int i=1; i<=N; i++) B[i].first = s();
for(int i=1; i<=N; i++) B[i].second.first = s();
for(int i=1; i<=N; i++) B[i].second.second = s();
sort(B+1, B+N+1);
for(int i=1; i<=N; i++) comp[i] = B[i].second.first;
sort(comp+1, comp+N+1);
for(int i=1; i<=N; i++) B[i].second.first = (int)( lower_bound(comp+1, comp+N+1, B[i].second.first) - comp );
for(int i=1; i<=N; i++) comp[i] = B[i].second.second;
sort(comp+1, comp+N+1);
for(int i=1; i<=N; i++) B[i].second.second = (int)( lower_bound(comp+1, comp+N+1, B[i].second.second) - comp );
int ans = 0;
for(int i=1; i<=N; i++) comp2[B[i].second.first/ROOT].push_back(B[i].second.second);
for(int i=0; i<=N/ROOT; i++) sort(comp2[i].begin(), comp2[i].end());
for(int i=1; i<=N; i++) {
int idx = B[i].second.first / ROOT;
int mx = 1;
for(int j=0; j<idx; j++) {
mx = max(mx, S[j].RMQ(1, (int)(upper_bound(comp2[j].begin(), comp2[j].end(), B[i].second.second) - comp2[j].begin()) ) + 1);
}
for(auto it : bucket[idx]) {
if(it.second.first < B[i].second.first && it.second.second < B[i].second.second) mx = max(mx, it.first + 1);
}
bucket[idx].push_back(tr(mx, B[i].second));
S[idx].update((int)(lower_bound(comp2[B[i].second.first/ROOT].begin(), comp2[B[i].second.first/ROOT].end(), B[i].second.second) - comp2[B[i].second.first/ROOT].begin()) + 1, mx);
ans = max(ans, mx);
}
printf("%d\n", ans);
}
}
