##for i in range(2):
##    print(f'i={i}')
##    for j in range(3):
##        print(f'{i} {j}')
##
##for i in range(2):
##    print(f'i={i}')
##    for j in range(1,3):
##        print(f'{i} {j}')


for i in range(5):
    print(f'i={i}')
    for j in range(0,5-i):
        print(f'{i} {j}')