import sys

n, m = [int(x) for x in input().split()]
forward = []
backward = []
for i, line in enumerate(sys.stdin):
    a, b = [int(x) for x in line.split()]
    if a < b:
        forward.append(i+1)
    else:
        backward.append(i+1)

print(len(forward))
print("\n".join(str(i) for i in forward))