#include <bits/stdc++.h> using namespace std; #define int long long const int INF = 1e18; const int MOD = 1e9+7; const int MAXN = 2e5; int n, m; bool stat[MAXN+5]; void mulaidarinol(){} void solve(){ cin >> n; n--; for(int i = 1; i <= n; i++) stat[i] = 1; int ans = 0; cin >> m; while(m--){ int evnt; cin >> evnt; if(evnt > 0){ if(stat[evnt] == 0){ ans++; for(int i = 1; i <= n; i++){ if(i == evnt) continue; stat[i] = 1; } }else{ stat[evnt] = 0; } }else{ evnt = -evnt; if(stat[evnt] == 0){ stat[evnt] = 1; } } // cerr << endl; // cerr << evnt << " : "; // for(int i = 1; i <= n; i++) cerr << stat[i] << ' '; } cerr << "=> "; cout << ans << endl; } signed main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int tc = 1; // cin >> tc; while(tc--){ // mulaidarinol(); solve(); } return 0; }