#include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
using namespace std;
using ll = long long;
using ld = long double;
using V = vector<int>;
using Vll = vector<ll>;
using Vld = vector<ld>;
using Vbo = vector<bool>;
using VV = vector<V>;
using VVll = vector<Vll>;
using VVld = vector<Vld>;
using VVbo = vector<Vbo>;
using VVV = vector<VV>;
using VVVll = vector<VVll>;
using P = pair<int, int>;
using Pll = pair<ll, ll>;
using Pld = pair<ld, ld>;
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define rep(i, n) rep2(i, 0, n)
#define drep(i, n) drep2(i, n, 0)
#define all(a) (a).begin(), (a).end()
struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
template<typename T> inline int sz(T &x) { return x.size(); }
template<typename T> inline bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }
template<typename T> inline bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p) { is >> p.first >> p.second; return is; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p) { os << '(' << p.first << ", " << p.second << ')'; return os; }
template<typename T> istream &operator>>(istream &is, vector<T> &v) { for (auto &e : v) is >> e; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }
template<typename T> inline int count_between(vector<T> &a, T l, T r) { return lower_bound(all(a), r) - lower_bound(all(a), l); } // [l, r)
inline int fLog2(const int x) { assert(x > 0); return 31-__builtin_clz(x); } // floor(log2(x))
inline int fLog2(const ll x) { assert(x > 0); return 63-__builtin_clzll(x); }
inline int cLog2(const int x) { assert(x > 0); return (x == 1) ? 0 : 32-__builtin_clz(x-1); } // ceil(log2(x))
inline int cLog2(const ll x) { assert(x > 0); return (x == 1) ? 0 : 64-__builtin_clzll(x-1); }
inline int popcount(const int x) { return __builtin_popcount(x); }
inline int popcount(const ll x) { return __builtin_popcountll(x); }
void fail() { puts("-1"); exit(0); }
const int INF  = 1<<30;
const ll INFll = 1ll<<62;
const ld EPS   = 1e-10;
const ld PI    = acos(-1.0);
// const int MOD  = int(1e9)+7;
// const int MOD  = 998244353;


int main() {
  int n, m; cin >> n >> m;
  VV a(n, V(m)); cin >> a;
  rep(i, n) rep(j, m) --a[i][j];
  rep(i, n) reverse(all(a[i]));


  auto f = [&] (ll x) {
    auto b = a;
    Vbo deled(m);
    while (true) {
      VV idx(m);
      rep(i, n) idx[b[i].back()].push_back(i);
      int j = -1;
      int cm = 0;
      rep(i, m) if (chmax(cm, sz(idx[i]))) j = i;
      if (cm <= x) return true;
      deled[j] = true;
      for (auto i : idx[j]) {
        while (!b[i].empty() && deled[b[i].back()]) b[i].pop_back();
        if (sz(b[i]) == 0) return false;
      }
    }
    assert(1 == 0);
    return false;
  };

  ll ok = n;
  ll ng = 0;
  while (llabs(ok - ng) > 1) {
    ll md = (ok + ng) >> 1;
    if (f(md)) ok = md;
    else ng = md;
  }

  cout << ok << '\n';
  return 0;
}

Measured memory_bytes: 4376