def extgcd(a, b): if b: d, y, x = extgcd(b, a%b) y -= (a/b)*x return d, x, y else: return a, 1, 0 inputs = lambda:map(int, raw_input().split()) p, q = inputs() if p<q: p,q = q,p g, a, b = extgcd(p, q) n = input() ans = 0 for i in xrange(n): xi, yi = inputs() if p==0: ans += (xi==yi==0) elif q==0: ans += (xi%p==0 and yi%p==0) else: if xi%g==0 and yi%g==0: xr = xi/g; yr = yi/g x = xr*a; y = xr*b dx = q/g; dy = -p/g z = yr*b; w = yr*a dz = p/g; dw = -q/g #print x, dx, y, dy #print z, dz, w, dw if(((x+z)%2==0 and (y+w)%2==0) or ((x+z+dx)%2==0 and (y+w+dy)%2==0) or ((x+z+dz)%2==0 and (y+w+dw)%2==0) or ((x+z+dx+dz)%2==0 and (y+w+dy+dw)%2==0)): ans += 1 print ans