#include <iostream>
#include <iomanip>
#include <string>
#include <math.h>
#include <algorithm>
#include <cstring>
#include <numeric>
#include <vector>
#include <bitset>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <unordered_map>
#include <unordered_set>
using namespace std;
#define dbg(x) cerr<<#x<<": "<<x<<"\n";
/*
Seventh Heaven
INOHA
*/
void solve(){
int n, q; cin>>n>>q;
map<int, int>freq;
map<int, vector<int>>ans;
int aux=0;
for(int i=0 ; i<q ; i++){
int curr; cin>>curr;
if(curr<0){
freq[curr]=0;
}else{
ans[curr].push_back(freq[curr]);
freq[curr]++;
}
}
for(auto it:ans){
vector<int>v=it.second;
int curr=0;
for(int i=0 ; i<(int)v.size()-1 ; i++){
if(v[i]>v[i+1]) curr+=v[i];
}
aux=max(aux, curr+v.back());
}
cout<<aux<<"\n";
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
solve();
return 0;
}
