import math

def main():
    import sys
    input = sys.stdin.read().split()
    idx = 0
    P = int(input[idx]); idx += 1
    Q = int(input[idx]); idx += 1
    N = int(input[idx]); idx += 1
    count = 0

    for _ in range(N):
        X = int(input[idx]); idx += 1
        Y = int(input[idx]); idx += 1

        if P == 0 and Q == 0:
            if X == 0 and Y == 0:
                count += 1
            continue

        if P == 0:
            if Q != 0 and X % Q == 0 and Y % Q == 0:
                count += 1
            continue

        if Q == 0:
            if P != 0 and X % P == 0 and Y % P == 0:
                count += 1
            continue

        # Both P and Q are non-zero
        g = math.gcd(P, Q)
        if X % g != 0 or Y % g != 0:
            continue

        x = X // g
        y = Y // g

        sum_xy = x + y
        diff_xy = x - y

        # Compute gcd of (P + Q) and |P - Q|
        g2 = math.gcd(P + Q, abs(P - Q))

        if sum_xy % g2 == 0 and diff_xy % g2 == 0:
            count += 1

    print(count)

if __name__ == '__main__':
    main()