## solution

binary indexed treeやsegment treeを使う。$O(N \log \max W_i)$。座標圧縮すれば$O(N \log N)$にできるが不要。

std::multisetでは通らないはず。$n$-th elementやiterator間の距離を取る関数を触れないので$O(N^2)$になりそう。

## implementation

#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#define repeat(i,n) for (int i = 0; (i) < (n); ++(i))
#define whole(f,x,...) ([&](decltype((x)) whole) { return (f)(begin(whole), end(whole), ## __VA_ARGS__); })(x)
using namespace std;

template <typename T>
struct binary_indexed_tree { // on monoid
vector<T> data;
T unit;
function<T (T,T)> append; // associative
template <typename F>
binary_indexed_tree(size_t n, T a_unit, F a_append) : data(n, a_unit), unit(a_unit), append(a_append) {}
void point_append(size_t i, T w) { // data[i] += w
for (size_t j = i+1; j <= data.size(); j += j & -j) data[j-1] = append(data[j-1], w);
}
int initial_range_concat(size_t i) { // sum [0, i)
T acc = unit;
for (size_t j = i; 0 < j; j -= j & -j) acc = append(acc, data[j-1]);
return acc;
}
T point_get(size_t i) {
return initial_range_concat(i+1) - initial_range_concat(i);
}
};

int main() {
int n, k; cin >> n >> k;
vector<int> ws(n); repeat (i,n) cin >> ws[i];
int w_max = max(*whole(max_element, ws), - *whole(min_element, ws));
binary_indexed_tree<int> bit(w_max+1, int(), plus<int>());
for (int w : ws) {
int i = w_max - abs(w);
if (w > 0) {
if (bit.initial_range_concat(i+1) < k) {
bit.point_append(i, 1);
}
} else if (w < 0) {
if (bit.point_get(i)) {
bit.point_append(i, -1);
}
}
}
cout << bit.initial_range_concat(w_max) << endl;
return 0;
}