#include <iostream>
using namespace std;
int main() {
int n ;
cin>>n;
int target;
cin>>target;
int arr[n];
for(int i = 0; i< n ; i++){
cin>>arr[i];
}
int count = 0;
for(int i = 0; i< n ; i++){
for(int j = i+1;j< n ; j++){
if(arr[i]-arr[j] == target){
count +=1;
}
}
}
cout << count;
return 0;
}
I2luY2x1ZGUgPGlvc3RyZWFtPgp1c2luZyBuYW1lc3BhY2Ugc3RkOwoKaW50IG1haW4oKSB7CglpbnQgbiA7CgljaW4+Pm47CglpbnQgdGFyZ2V0OwoJY2luPj50YXJnZXQ7CglpbnQgYXJyW25dOwoJZm9yKGludCBpID0gMDsgaTwgbiA7IGkrKyl7CgkJY2luPj5hcnJbaV07Cgl9CglpbnQgY291bnQgPSAwOwoJZm9yKGludCBpID0gMDsgaTwgbiA7IGkrKyl7CgkJZm9yKGludCBqID0gaSsxO2o8IG4gOyBqKyspewoJCQlpZihhcnJbaV0tYXJyW2pdID09IHRhcmdldCl7CgkJCQljb3VudCArPTE7CgkJCX0KCQl9Cgl9Cgljb3V0IDw8IGNvdW50OwoKICAgIHJldHVybiAwOwp9