a, b, c, d = map(int, input().split())
n = int(input())
xy = [list(map(int, input().split())) for _ in range(n)]
# 横移動
if a == c == 0:
    while b > 0:
        d, b = b, d % b
else:
    if a < c:
        a, b, c, d = c, d, a, b
    while c > 0:
        r = a // c
        a, b, c, d = c, d, a - r * c, b - r * d
    d = abs(d)
    nxy = []
    for x, y in xy:
        nxy.append([x % a, y - b * (x // a)])
    xy = nxy
ki = set()
# 縦移動
if d:
    for x, y in xy:
        ki.add((x, y % d))
else:
    for x, y in xy:
        ki.add((x, y))
print(len(ki))