#include using namespace std; #define int long long #define mp make_pair templatebool chmax(T &a, const T &b) { if (abool chmin(T &a, const T &b) { if (b struct BinaryIndexTree{ int n; vector bit; vector org; BinaryIndexTree(int si): bit(si+1, 0), org(si+1, 0) { n = si; }; void add(int idx, T v){ org[++idx] += v; for(int i = idx;i <= n;i+=i&-i) bit[i] += v; } void update(int idx, T v){ T vv = v - org[++idx]; org[idx] = v; for(int i = idx;i <= n;i+=i&-i) bit[i] += vv; } T sum(int a){ T ret = 0; for(int i = a;i > 0;i-=i&-i) ret += bit[i]; return ret; } T sum(int l, int r) { return sum(r)-sum(l); }; }; int dfs(int l, int r){ if(r-l == 1) return a[l]*2 == k ? 1 : 0; int mid = (r+l)/2; int ans = dfs(l, mid) + dfs(mid, r); vector,int>>> b(mid-l), c(r-mid); for(int i = l;i < mid;i++) b[i-l].first = a[i]; for(int i = mid;i < r;i++) c[i-mid].first = a[i]; int ln = b.size(); int rn = c.size(); int mi = INT_MAX; int micnt = 0; for(int i = ln-1;i >= 0;i--){ if(mi > b[i].first){ mi = b[i].first; micnt = 1; }else if(mi == b[i].first){ micnt++; } b[i].second = {{mi, micnt}, ln-i}; } sort(b.begin(), b.end()); BinaryIndexTree bit1_c(ln), bit1_s(ln); BinaryIndexTree bit2_c(ln), bit2_s(ln); for(int i = 0;i < ln;i++){ if(b[i].second.first.second == 1){ bit2_c.update(i, 1); bit2_s.update(i, b[i].second.second); } bit1_c.update(i, 1); bit1_s.update(i, b[i].second.second); } mi = INT_MAX; micnt = 0; for(int i = 0;i < rn;i++){ if(mi > c[i].first){ mi = c[i].first; micnt = 1; }else if(mi == c[i].first){ micnt++; } int ll, m1, m2, rr; pair, int>> x = mp(k-c[i].first, mp(mp(-1, -1), -1)); ll = lower_bound(b.begin(), b.end(), x) - b.begin(); x = mp(k-c[i].first, mp(mp(mi, -1), -1)); m1 = lower_bound(b.begin(), b.end(), x) - b.begin(); x = mp(k-c[i].first, mp(mp(mi+1, -1), -1)); m2 = lower_bound(b.begin(), b.end(), x) - b.begin(); x = mp(k-c[i].first+1, mp(mp(-1, -1), -1)); rr = lower_bound(b.begin(), b.end(), x) - b.begin(); int atmp = bit2_c.sum(ll, m1)*(i+1) + bit2_s.sum(ll, m1); if(micnt == 1){ atmp += bit1_c.sum(m2, rr)*(i+1) + bit1_s.sum(m2, rr); } ans += atmp; } return ans; } signed main(){ int n; cin >> n >> k; for(int i = 0;i < n;i++){ cin >> a[i]; } cout << dfs(0, n) << endl; return 0; }