include<bits/stdc++.h>

using namespace std;
using ll = long long;

define f0(i, n) for(int i = 0; i < n; i++)

define f1(i, n) for(int i = 1; i <= n; i++)

define fi first

define se second

typedef string str;
typedef pair<int, int> pii;
typedef set<int> si;
typedef vector<int> vi;
typedef map<int, int> mii;
// Dãy con có tổng <= s => độ dài max
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, k; cin >> n >> k;
int a[n];
f0(i, n) cin >> a[i];
int l = 0, r = n - 1;
int dem = 0;
while(l < r){
if(a[l] + a[r] == k){
int dem1 = 0;
while(a[l] == k - a[r]){
++dem1;
++l;
}
int dem2 = 0;
while(a[r] == k - a[l - 1]){
++dem2;
--r;
}
dem += 1ll * dem1 * dem2;
}
else if(a[l] + a[r] < k) ++l;
else --r;
}
cout << dem << endl;
}