#include <bits/stdc++.h> // #pragma GCC optimize("Ofast,unroll-loops,O3") // #pragma GCC target("avx,avx2,fma") using namespace std; // using namespace __gnu_pbds; // using namespace __gnu_cxx; // template <typename T> // using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>; // template <typename T> // using ordered_multiset = tree <T, null_type, less_equal <T>, rb_tree_tag, tree_order_statistics_node_update>; using ll = long long; using ld = long double; using ull = unsigned long long; using uint = unsigned int; using i128 = __int128_t; istream& operator>>(istream& is, i128& x) { long long a; is >> a; x = (i128) a; return is; } ostream& operator<<(ostream& os, i128& x) { long long a = (long long) x; os << a; return os; } template <typename T> ostream& operator<<(ostream& is, vector <T>& a) { for (uint i = 0; i < a.size(); ++i) is << a[i] << " "; return is; } #ifdef LOCAL # define DEBUG(x) cerr << "(" << __LINE__ << ") " << #x << ": " << x << endl; #else # define DEBUG(x) #endif // const ll inf = 1e18 + 1e16; const int inf_t = 1e9 + 7; const ll mod = 1e9 + 7; signed main() { #ifdef LOCAL freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); #endif ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); int n; cin >> n; int q; cin >> q; int cur = 0; int bal[n] = {0}; int prev[n] = {0}; int last[n] = {-1}; for (int i = 0; i < q; ++i) { int x; cin >> x; if (x > 0) { if (bal[x] == 1 && last[x] == cur) { ++last[x]; ++cur; bal[x] = 1; } else { bal[x] = 1; last[x] = cur; } } else { x = -x; bal[x] = 0; last[x] = cur; } } cout << cur; }