```c
#include<iostream>
#include<cstdio>
#include<vector>
#include<cmath>
#define int long long
using namespace std;
int n,m,s,l,i,j,a[3000000],x,ans,c;
vector<int>v[1000000];
vector<int>cnt[1000000];
bool flag;
signed main()
{
scanf("%lld%lld",&n,&c);
for(i=1;i<=n;i++)
{
scanf("%lld",&a[i]);
x=abs(a[i])%999983;
l=v[x].size();
flag=true;
for(j=0;j<l;j++)
{
if(v[x][j]==a[i])
{
flag=false;
cnt[x][j]++;
break;
}
}
if(flag)
{
v[x].push_back(a[i]);
cnt[x].push_back(1);
}
}
for(i=1;i<=n;i++)
{
x=abs(c+a[i])%999983;
l=v[x].size();
s=0;
for(j=0;j<l;j++)
{
if(v[x][j]==c+a[i])
{
s=cnt[x][j];
break;
}
}
ans+=s;
}
printf("%lld",ans);
}
```
by K__ON @ 2022-08-18 21:25:33