s=input()
if s == "":
    exit()
elif "=" not in s:
     exit()
else:
    try:
        LHS,RHS = s.split('=')
    except ValueError:
        exit()

for i in range(int(input())):
    try:
        X,Y=map(int,input().split())
    except ValueError:
        continue
    if 'y' in LHS:
        LHS = LHS.replace('y', '1')
        LHS_NEW=int(LHS)*Y
    else:
        LHS_NEW=int(LHS)

    if 'x' in RHS:
        L,R = RHS.split('x')
        L_NEW = int(L)*X
        if R!='':
            R_NEW=int(R)
        else:
            R_NEW=0
        RHS_NEW=L_NEW + R_NEW
    else:
        RHS_NEW=int(RHS)
    if LHS_NEW==RHS_NEW:
        print("YES")
    else:
        print("NO")