with open('input20.txt','r') as f:
    inp = f.read().splitlines(keepends=False)

sequence = []
decryptionKey = 811589153

for i in range(len(inp)):
    if int(inp[i]) == 0:
        zero = (i, int(inp[i]))
    sequence.append((i, int(inp[i]) * decryptionKey))
numbers = sequence.copy()

for number in sequence:
    if sequence.count(number) > 1:
        print('!')

for i in range(10):
    for number in numbers:
        index = sequence.index(number)
        _number = number[1]
        newIndex = index + _number
        sequence.pop(index)
        newIndex %= len(sequence)
        sequence.insert(newIndex, number)

number = sequence.index(zero) + 1000
_sum = 0
for i in range(3):
    number %= len(sequence)
    #print(sequence[number])
    _sum += sequence[number][1]
    number += 1000

print(_sum)