#include using namespace std; typedef long long int ll; typedef pair P; typedef pair Pll; typedef vector Vi; typedef tuple T; #define FOR(i,s,x) for(int i=s;i<(int)(x);i++) #define REP(i,x) FOR(i,0,x) #define ALL(c) c.begin(), c.end() #define DUMP( x ) cerr << #x << " = " << ( x ) << endl #define INF 2147483647 const int MAX_N = 1000000; /* Range Sum Query by FenwickTree(Binary Indexed Tree) total number: n queries: 1. update(i, val): add val to i-th value 2. query(n): sum(bit[0] + ... + bit[n-1]) complexity: O(log n) Self-balancing binary search tree or Segment Tree can do the same, it takes longer to program and complexity also increases. Thanks: http://hos.ac/slides/20140319_bit.pdf used in ARC031 C, indeednow finalB E, DSL2B(AOJ) */ int dat[MAX_N + 1]; struct RangeSumQuery { int N; RangeSumQuery(int N) : N(N) { } void update(int k, int val) { for (int x = k; x < N; x |= x + 1) { dat[x] += val; } } int query(int k) { int ret = 0; for (int x = k - 1; x >= 0; x = (x & (x + 1)) - 1) { ret += dat[x]; } return ret; } }; int main() { // use scanf in CodeForces! cin.tie(0); ios_base::sync_with_stdio(false); int N, K; cin >> N >> K; RangeSumQuery fwt(1000001); REP(i, N) { int W; cin >> W; if (W < 0) { W = abs(W); if (fwt.query(W+1) - fwt.query(W) > 0) { fwt.update(W, -1); } } else { if (fwt.query(1000001) - fwt.query(W) < K) { fwt.update(W, 1); } } } cout << fwt.query(1000001) << endl; return 0; }