def calcula_quadrant(x, y):
    if x > 0 and y > 0:
        q = 'I'
    elif x < 0 and y > 0:
        q = 'II'
    elif x < 0 and y < 0:
        q = 'III'
    elif x > 0 and y < 0:
        q = 'IV'
    elif x == 0 and y == 0:
        q = 'O'
    elif y == 0:
        q = 'X'
    else:
        q = 'Y'
    return q