import aoclib

#my_input = [1721, 979, 366, 299, 675, 1456]  # debug input
my_input = aoclib.getInputLineAsArray(1, int)

globalBreak = False
while len(my_input) > 0:
    try_value = my_input.pop()
    for value in my_input:
        if try_value + value == 2020:
            aoclib.printSolution(1, 1, try_value * value)
            globalBreak = True
            break

    if globalBreak:
        break