#include using namespace std; int N, K; #define MX (1000010) class BIT { private: vector bit; int size; public: BIT(int n) : size(n) { bit.resize(n+1); } int sum(int i) { int s = 0; while(i > 0) { s += bit[i]; i -= i & -i; } return s; } void add(int i, int x) { while(i <= size) { bit[i] += x; i += i & -i; } } }; int main() { cin >> N >> K; static BIT b(MX+1); for(int i=0; i> W; if(W > 0) { if(b.sum(MX)-b.sum(W-1) < K) { b.add(W, 1); } } else { W *= -1; if(b.sum(W)-b.sum(W-1) > 0) { b.add(W, -1); } } } cout << b.sum(MX) << endl; return 0; }