import sys
import numpy as np

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(readline())
XY = np.array(read().split(), np.int64)

X, Y = XY[::2], XY[1::2]

key1 = X % 9
key2 = Y % 5
key3 = ((X // 9) + (Y // 5)) & 1

key = key1 * 10 + key2 * 2 + key3
most_freq = np.bincount(key).argmax()
ans = np.where(key == most_freq)[0]

print(len(ans))
print('\n'.join(map(str, ans.tolist())))