import sys
input = sys.stdin.readline
N,M,P,Q = map(int,input().split())
XF = [tuple(map(int,input().split())) for i in range(Q)]
for x,f in XF:
    if x%P==0:
        print(0 if f else M)
        continue
    inv_x = pow(x,P-2,P)
    y = f*inv_x % P
    d,m = divmod(M,P)
    print(d + int(m >= y) - (f == 0))