# # Q: How to find all pairs in an array of integers whose sum is equal to the given number?
# number = 30
# n = [10, 11, 12, 13, 14, 17, 18, 19]
# i=0
# a=[]
# while i<len(n):
#     j=4
#     while j<len(n):
#         if n[i]+n[j]==number:
#             a.append([n[i],n[j]])
#         j=j+1
#     i=i+1
# print(a)


