According to the regulations of Berland's army, a reconnaissance unit should consist of exactly two soldiers. Since these two soldiers shouldn't differ much, their heights can differ by at most *d* centimeters. Captain Bob has *n* soldiers in his detachment. Their heights are *a*<sub class="lower-index">1</sub>, *a*<sub class="lower-index">2</sub>, ..., *a*<sub class="lower-index">*n*</sub> centimeters. Some soldiers are of the same height. Bob wants to know, how many ways exist to form a reconnaissance unit of two soldiers from his detachment.

Ways (1, 2) and (2, 1) should be regarded as different.
The first line contains two integers *n* and *d* (1 ≤ *n* ≤ 1000, 1 ≤ *d* ≤ 10<sup class="upper-index">9</sup>) — amount of soldiers in Bob's detachment and the maximum allowed height difference respectively. The second line contains *n* space-separated integers — heights of all the soldiers in Bob's detachment. These numbers don't exceed 10<sup class="upper-index">9</sup>.
#include <stdio.h>
#include<stdlib.h>
int main()
{int *n,*d,*t,nb,i,j;
n=(int*)malloc(sizeof(int));
d=(int*)malloc(sizeof(int));
scanf("%d",n);
t=(int*)malloc(sizeof(int)*(*n));

scanf("%d",d);
for(i=0;i<(*n);i++)
    scanf("%d",t+i);
for(i=0,nb=0;i<((*n)-1);i++)
  for(j=i+1;j<(*n);j++)
        if (abs(t[i]-t[j])<=*d) nb++;
free(n);
free(d);
free(t);
printf("%d",2*nb);
return 0;
}
