#include <iostream>
#include <sstream>
#include <fstream>

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cctype>
#include <cstring>

#include <algorithm>
#include <numeric>
#include <functional>
#include <string>
#include <vector>
#include <deque>
#include <stack>
#include <queue>
#include <list>
#include <map>
// #include <unordered_map>
#include <set>
#include <utility>
#include <bitset>
#include <limits>
#include <climits>
using namespace std;

#ifdef DEBUG
#define NDEBUG
#include "cout11.h"
#endif
#undef NDEBUG
#include <cassert>

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;

#define sz(a)  int((a).size())
#define pb  push_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define ALL(c)  (c).begin(),(c).end()
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))

#define INTSPACE 11
char _buf[INTSPACE*1000000 + 3];  // ここ要確認

int loadint() {
    if (fgets(_buf, INTSPACE+3, stdin)==NULL) return 0;
    return atoi(_buf);
}
int loadvec(vector<int>& v, int N=-1) {
    if (N == -1) {
        N = loadint();
        if (N==0) return 0;
    }
    int bufsize = INTSPACE*N + 3;
    if (fgets(_buf, bufsize, stdin)==NULL) return 0;
    v.resize(N);

    int i=0;
    bool last = false;
    for (char *p=&_buf[0]; ;) {
        char *q = p;
        while (*q > ' ') ++q;
        if (*q == 0x0D || *q == 0x0A) last = true;
        *q = 0;
        v[i++] = atoi(p);
        if (last || i == N) break;
        p = q+1;
    }
    // assert(i <= N);
    return i;
}

int N, M;
vector<vector<int>> a;

int p(int x) {
    vector<int> head(N, 0);
    vector<vector<int>> sink(M);
    vector<bool> available(M, true);

    queue<int> q;
    rep(n, N) q.push(n);
    while (true) {
        while (!q.empty()) {
            int n = q.front(); q.pop();
            while (head[n] < M && !available[a[n][head[n]]]) ++head[n];
            if (head[n] == M) return false;
            int m = a[n][head[n]++];
            sink[m].pb(n);
        }
#ifdef VERBOSE
        cout << sink << endl;
#endif
        rep(m, M) {
            if (sink[m].size() > x) {
                available[m] = false;
                for (int i : sink[m]) q.push(i);
                sink[m].clear();
            }
        }
        if (q.empty()) return true;
    }
    return false;
}

int main() {
    vector<int> tmp;
    loadvec(tmp, 2);
    N = tmp[0]; M = tmp[1];
    a.resize(N);
    rep(n,N){
        loadvec(a[n], M);
        rep(i, M) a[n][i]--;
    }

    int lo=0, hi=N; // lo:x hi:o
    while (lo+1 < hi) {
        int mi = (lo + hi) / 2;
        bool pm = p(mi);
#ifdef VERBOSE
        printf("[%d %d], p(%d)=%d\n", lo, hi, mi, pm);
#endif
        if (pm) {
            hi = mi;
        } else {
            lo = mi;
        }
    }

    printf("%d\n", hi);
    return 0;
}


Measured memory_bytes: 1280