哎，听取WA声一片呀！

#include<bits/stdc++.h>
#define int long
using namespace std;
int n, c, x, ans;
map<int, int> mp;
inline int read()
{
	char cc = getchar();
	int f = 1;
	int ans = 0;
	while (cc < '0' || cc>'9')
	{
		if (cc == '-')
		{
			f = -1;
		}
		cc = getchar();
	}

	while (cc >= '0' && cc <= '9')
	{
		ans = (ans << 1) + (ans << 3) + (cc - '0');
		cc = getchar();
	}

	return f * ans;
}
inline void write(int x)
{
	if (x < 0)
	{
		putchar('-');
		x = -x;
	}
	if (x > 9)
		write(x / 10);
	putchar(x % 10 + '0');
}
signed main()
{
    n=read();
    c=read();
    for(int i = 1; i <= n; i++)
    {
        x=read();
        mp[x-c]++;
    }
    for(int i = 1; i <= n; i++)
    {
        ans += mp[i];
    }
    write(ans);
    return 0;
}