Задача C. Чистые носки

(n,d) = map(int,input().split())
a = sorted(list(map(int,input().split())))
q = 0
i = 0
z = 0
for i in range(i,len(a)-1):
    if a[i]!=-1:
        for c in range(z,i+d+1):
            z = i+1
            if a[z]!=-1:
                if abs(a[z]-a[i])<=d:
                    a[z] = -1
                    a[i] = -1
                    q +=1
print(q)