/**
III U U N N DDDD EEEEE RRRR SSSS TTTTT AAAAA N N DDDD I TTTTT N N OOO W W
I U U NN N D D E R R S T A A NN N D D I T NN N O O W W
I U U N N N D D EEEE RRRR SSSS T AAAAA N N N D D I T N N N O O W W W
I U U N NN D D E R R S T A A N NN D D I T N NN O O WW WW
III UUUUU N N DDDD EEEEE R R SSSS T A A N N DDDD I T N N OOO W W
**/
//18.09.25
#include <bits/stdc++.h>
// #pragma optimize("g", on)
// #pragma GCC optimize ("inline")
// #pragma GCC optimize ("Ofast")
// #pragma GCC optimize ("unroint-loops")
// #pragma GCC optimize ("03")
// #pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,avx2,mmx,fma,avx,tune=native")
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
using namespace std;
// using namespace __gnu_pbds;
#define F first
#define ent '\n'
#define S second
#define no "NO\n"
#define in insert
#define yes "YES\n"
#define pb push_back
#define int long long
#define sz(w) w.size()
#define pii pair <int, int>
#define all(w) w.begin(), w.end()
#define rall(w) w.rbegin(), w.rend()
#define Yeah ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
const int MOD = 998244353, M = 4e5 + 7, N = 1e5 + 7, INF = 1e18, inf = 1e9 + 7, LOG = 20 , mod = 1e9 + 7 ;
// find_by_order idx and get s[idx], idx from 0
// order_of_key cnt of x >
// template <typename T>
// using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
// mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void accepted() {
int n , q ;
cin >> n >> q ;
set <int> s ;
int ans = 0 ;
while(q -- ) {
int x ;
cin >> x ;
if(x > 0) {
if(s.find(x) != s.end()) {
ans ++ ;
s.clear() ;
}
s.in(x) ;
}
else {
x *= -1 ;
s.erase(x) ;
}
}
cout << ans ;
}
signed main() {
Yeah
// PLS NeverGiveUp
// freopen("cowpatibility.in", "r", stdin) ;
// freopen("cowpatibility.out", "w", stdout) ;
int T = 1 ;
// cin >> T ;
while(T--) {
accepted();
cout << endl ;
}
}
/**
**/
