import math n = int(input()) arr = list(map(int, input().split(" "))) x = 0 y = 0 st = [[0,0]] * int((math.factorial(n))/4) for i in range(n): for j in range(i+1,n): # if i + j == 0 # print(arr[i],i , arr[j],j) print([i - j]) print(st)