def in_10(x1, y1, x2, y2):
    return (x1 - x2) ** 2 + (y1 - y2) ** 2 < 100


n = int(input())
info = [list(map(int, input().split())) for i in range(n)]
MAX_LEN = 500


is_seated = [[-1] * MAX_LEN for _ in range(MAX_LEN)]
for i in range(n):
    x, y = info[i]
    x -= 1
    y -= 1
    is_seated[x][y] = i

dp = [[0] * MAX_LEN for i in range(MAX_LEN)]
ru = [0] * (MAX_LEN + 1)

for x in range(MAX_LEN):
    for y in range(MAX_LEN):
        if is_seated[x][y] == -1:
            continue
        else:
            dp[x][y] = 1
            dp[x][y] = max(ru[max(x + 1 - 10, 0)] + 1, dp[x][y])
            for x2 in range(max(x - 10, 0), x):
                for y2 in range(MAX_LEN):
                    if in_10(x, y, x2, y2):
                        continue
                    dp[x][y] = max(dp[x2][y2] + 1, dp[x][y])
            for y2 in range(y):
                if in_10(x, y, x, y2):
                    continue
                dp[x][y] = max(dp[x][y2] + 1, dp[x][y])

    tmp_max = 0
    for y in range(n):
        tmp_max = max(dp[x][y], tmp_max)
    ru[x + 1] = max(ru[x], tmp_max)

"""
# 復元する
max_ = 0
ans = []
for x in range(MAX_LEN)[::-1]:
    for y in range(MAX_LEN)[::-1]:
        if max_ == 0 and dp[x][y] > 0:
            ans.append(is_seated[x][y] + 1)
            max_ = dp[x][y]
        elif max_ - 1 == dp[x][y] and dp[x][y] != 0:
            ans.append(is_seated[x][y] + 1)
            max_ = dp[x][y]
print(len(ans))
print(*ans)"""