state = [3, 7]

puzzle_in = '077201'

elf_1 = 0
elf_2 = 1

def print_state():
    out = ''
    for i, el in enumerate(state):
        if i == elf_1:
            out += '(' + str(el) + ')'
        elif i == elf_2:
            out += '[' + str(el) + ']'
        else:
            out += ' ' + str(el) + ' '
    print(out)

while 1:
    val_1 = state[elf_1]
    val_2 = state[elf_2]

    state.extend([ int(x) for x in list(str(val_1 + val_2)) ])

    test_1 = state[-6:]
    test_2 = state[-7:-1]

    # print(''.join([str(x) for x in test_1]), ''.join([str(x) for x in test_2]), puzzle_in)

    if ''.join([str(x) for x in test_1]) == puzzle_in:
        res = len(state) - 6
        break

    if ''.join([str(x) for x in test_2]) == puzzle_in:
        res = len(state) - 7
        break

    elf_1 = (1 + elf_1 + val_1) % len(state)
    elf_2 = (1 + elf_2 + val_2) % len(state)

    # print_state()

print(res)