#include <bits/stdc++.h> using namespace std; signed main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n, q; cin >> n >> q; map < int , vector < int > > adj; while(q--){ int x; cin >> x; adj[abs(x)].push_back(x); } int mx = 0; for(int i = 1; i <= n; i++){ int cnt = 0; vector < int > v = adj[i]; for(int i = 0; i < v.size(); i++){ if(v[i] < 0){ cnt = 0; } else { cnt++; } mx = max(mx, cnt); } } cout << max(mx - 1, 0) << endl; }