s = input()
for i in range(int(input())):
    X, Y = map(int, input().split())
    LHS, RHS = s.split('=')
    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 = 0
        else:
            R_NEW = int(R)
        RHS_NEW = L_NEW + R_NEW
    else:
        RHS_NEW = int(RHS)
    if LHS_NEW == RHS_NEW:
        print("YES")
    else:
        print("NO")