#include <cstdio>

 #include <iostream>

 #define LL long long

 int a[];

 int n, m, k;

 LL ans, f[][ << ];

 inline int read()

 {

     int x = , f = ;

     char ch = getchar();

     for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -;

     for(; isdigit(ch); ch = getchar()) x = (x << ) + (x << ) + ch - '';

     return x * f;

 }

 inline int abs(int x)

 {

     return x <  ? -x : x;

 }

 int main()

 {

     int i, j, S;

     n = read();

     k = read();

     m = ( << n) - ;

     for(i = ; i <= n; i++) a[i] = read();

     for(i = ; i <= n; i++) f[i][ << i - ] = ;

     for(S = ; S <= m; S++)

         for(i = ; i <= n; i++)

             if(( << i - ) & S)

                 for(j = ; j <= n; j++)

                     if(i ^ j && ( << j - ) & S && abs(a[i] - a[j]) > k)

                         f[i][S] += f[j][( << i - ) ^ S];

     for(i = ; i <= n; i++) ans += f[i][m];

     printf("%lld\n", ans);

     return ;

 }