#ifdef ONLINE_JUDGE #pragma GCC target("avx2,avx") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #endif #include using namespace std; using ll = long long; using ull = unsigned long long; using i128 = __int128_t; using pii = pair; using pll = pair; #define rep(i, n) for (int i = 0; i < (n); i++) #define all(x) (x).begin(), (x).end() constexpr char ln = '\n'; istream& operator>>(istream& is, __int128_t& x) { x = 0; string s; is >> s; int n = int(s.size()), it = 0; if (s[0] == '-') it++; for (; it < n; it++) x = (x * 10 + s[it] - '0'); if (s[0] == '-') x = -x; return is; } ostream& operator<<(ostream& os, __int128_t x) { if (x == 0) return os << 0; if (x < 0) os << '-', x = -x; deque deq; while (x) deq.emplace_front(x % 10), x /= 10; for (int e : deq) os << e; return os; } template ostream& operator<<(ostream& os, const pair& p) { return os << "(" << p.first << ", " << p.second << ")"; } template ostream& operator<<(ostream& os, const vector& v) { os << "{"; for (int i = 0; i < int(v.size()); i++) { if (i) os << ", "; os << v[i]; } return os << "}"; } template inline int SZ(Container& v) { return int(v.size()); } template inline void UNIQUE(vector& v) { v.erase(unique(v.begin(), v.end()), v.end()); } template inline bool chmax(T1& a, T2 b) { if (a < b) {a = b; return true ;} return false ;} template inline bool chmin(T1& a, T2 b) { if (a > b) {a = b; return true ;} return false ;} inline int topbit(int x) { return x == 0 ? -1 : 31 - __builtin_clz(x); } inline int topbit(long long x) { return x == 0 ? -1 : 63 - __builtin_clzll(x); } inline int botbit(int x) { return x == 0 ? 32 : __builtin_ctz(x); } inline int botbit(long long x) { return x == 0 ? 64 : __builtin_ctzll(x); } inline int popcount(int x) { return __builtin_popcount(x); } inline int popcount(long long x) { return __builtin_popcountll(x); } inline int kthbit(long long x, int k) { return (x>>k) & 1; } inline constexpr long long TEN(int x) { return x == 0 ? 1 : TEN(x-1) * 10; } namespace detail { template auto make_vector(vector& sizes, Tp const& x) { if constexpr (Nb == 1) { return vector(sizes[0], x); } else { int size = sizes[Nb-1]; sizes.pop_back(); return vector(size, make_vector(sizes, x)); } } } template auto make_vector(int const(&sizes)[Nb], Tp const& x = Tp()) { vector s(Nb); for (int i = 0; i < Nb; i++) s[i] = sizes[Nb-i-1]; return detail::make_vector(s, x); } inline void print() { cout << "\n"; } template inline void print(const vector& v) { for (int i = 0; i < int(v.size()); i++) { if (i) cout << " "; cout << v[i]; } print(); } template inline void print(const T& x, const Args& ... args) { cout << x << " "; print(args...); } #ifdef MINATO_LOCAL inline void debug_out() { cerr << endl; } template inline void debug_out(const T& x, const Args& ... args) { cerr << " " << x; debug_out(args...); } #define debug(...) cerr << __LINE__ << " : [" << #__VA_ARGS__ << "] =", debug_out(__VA_ARGS__) #define dump(x) cerr << __LINE__ << " : " << #x << " = " << (x) << endl #else #define debug(...) (void(0)) #define dump(x) (void(0)) #endif struct fast_ios { fast_ios() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_; //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// constexpr int INF = TEN(9)+1; int main() { int N,K; cin >> N >> K; vector A(N); rep(i,N) cin >> A[i]; ll ans = 0; auto rec=[&](auto self, int l, int r)->void { if (r-l==1) { if (A[l]*2==K) ans++; return; } int m = (l+r)/2; self(self,l,m); self(self,m,r); int MIN = INF; int cur_r = m; bool ok = true; map R; for (int pos = m-1; pos >= l; pos--) { if (MIN==A[pos]) ok = false; if (chmin(MIN,A[pos])) ok = true; if (!ok) continue; while (cur_r < r and A[cur_r] > MIN) { auto[len,cnt] = R[A[cur_r]]; len += cur_r - m + 1; cnt++; R[A[cur_r]] = pll(len,cnt); cur_r++; } if (R.count(K - A[pos])) { auto[len,cnt] = R[K - A[pos]]; ans += len + cnt*(m-pos); } } MIN = INF; int cur_l = m-1; ok = true; map L; for (int pos = m; pos < r; pos++) { if (MIN==A[pos]) ok = false; if (chmin(MIN,A[pos])) ok = true; if (!ok) continue; while (cur_l >= l and A[cur_l] > MIN) { auto[len,cnt] = L[A[cur_l]]; len += m - cur_l; cnt++; L[A[cur_l]] = pll(len,cnt); cur_l--; } if (L.count(K - A[pos])) { auto[len,cnt] = L[K - A[pos]]; ans += len + cnt*(pos-m+1); } } return; }; rec(rec,0,N); cout << ans << ln; }