#include using namespace std; #define FOR(i,a,b) for(int i=(a);i<(b);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) begin(v),end(v) template inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; } using ll = long long; using pii = pair; constexpr ll INF = 1ll<<30; constexpr ll longINF = 1ll<<60; constexpr ll MOD = 1000000007; constexpr bool debug = false; //---------------------------------// int main() { int N, X; cin >> N >> X; vector A(N); REP(i, N) scanf("%d", &A[i]); map mm; REP(i, N) ++mm[A[i]]; ll ans = 0; REP(i, N) ans += mm[X - A[i]]; cout << ans << endl; }