R = lambda:map(int,input().split())
n, k, l = R()
a = sorted(R())
s = c = 0
for i in range(n*k-1, -1, -1):
c += 1
if a[i]-a[0] <= l and c>=k:
s += a[i]
c -= k
print((s,0)[c>0])102. Binary Tree Level Order Traversal | 96. Unique Binary Search Trees |
75. Sort Colors | 74. Search a 2D Matrix |
71. Simplify Path | 62. Unique Paths |
50. Pow(x, n) | 43. Multiply Strings |
34. Find First and Last Position of Element in Sorted Array | 33. Search in Rotated Sorted Array |
17. Letter Combinations of a Phone Number | 5. Longest Palindromic Substring |
3. Longest Substring Without Repeating Characters | 1312. Minimum Insertion Steps to Make a String Palindrome |
1092. Shortest Common Supersequence | 1044. Longest Duplicate Substring |
1032. Stream of Characters | 987. Vertical Order Traversal of a Binary Tree |
952. Largest Component Size by Common Factor | 212. Word Search II |
174. Dungeon Game | 127. Word Ladder |
123. Best Time to Buy and Sell Stock III | 85. Maximal Rectangle |
84. Largest Rectangle in Histogram | 60. Permutation Sequence |
42. Trapping Rain Water | 32. Longest Valid Parentheses |
Cutting a material | Bubble Sort |